Every business needs to fill out paperwork the traditional way. Most of the paperwork, bills, and other important documents are kept or sent to clients and partners via packaging called envelopes.
Envelopes come in many types and sizes. While the contents of an envelope are the main thing, the importance of the business envelope size, however, cannot be overstated.
That’s because choosing the right envelope size really matters if you want to mail it through the postal system. Your envelope must not exceed the minimum or maximum business size envelope dimensions.
And with a variety of business envelope styles and each style having different sizes, it can be hard to keep track of which envelope is which size.
While the #10 envelopes are the standard business envelope size and they dominate the business mail space as the go-to envelope for mail, invoices, letters, and day-to-day office work; it won’t cut it for everything.
There are cases other than the “official use” when other envelope sizes need to be used, too. That is why knowing these envelope sizes is a must. So, to help you choose the right size, we will discuss business envelope size in this blog.
More so, we will create an envelope size chart for every envelope type. It will outline all the different sizes in inches, centimeters, and pixels for easy printing, mailing, folding, and fit.
We will also talk about the different business envelope types and what they are used for. This way, you will have all the envelope sizes you could possibly need to fit whatever you’re enveloping.
So, without any further ado, let’s get right into this.
What are Envelopes?
Just about everyone knows what an envelope is. However, there is a very small chance that some people might not know what it is.
And that is thanks to the world going all digital and emails becoming the primary means of delivering mail or documents.
So, to bring the cat out of the bag, envelopes are a form of paper packaging. They serve as a protective covering for sending paperwork.
More so, business envelopes are mainly considered a means of delivering mail or important business documents.
These paper containers are flat and rectangular in shape, most of them anyway. They are used to enclose papers, letters, cards, or other thin items. Envelopes have a flap that can be sealed with adhesive to secure the contents.
As for their existence, envelopes go as far back as the ancient civilizations of Mesopotamia, Egypt, and China. They have been used ever since then.
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Types of Envelopes and Their Sizes Chart
Now let’s get to the business end of things and discuss the different types of envelopes, their sizes in inches, centimeters, and pixels, and the purposes they are used for.
This way, you can choose the right envelope for your purpose and correctly size the items that will go inside it.
Therefore, here are the size charts and comparison table for all types of business envelopes, including what they hold, and what they are used for:
Business or Commercial Envelopes
The business envelope is the go-to envelope for most use cases, specifically being the standard #10 envelope size.
It is the one that people use for sending thicker packets, unfolded documents, and other items of different sizes.
However, there is more variety in commercial envelope size. There are also standard letter envelope sizes that people use to send letters.
So, if you are wondering what size is a letter envelope, then we will list all the business envelope dimensions of all envelopes here.
Business or Commercial Envelopes Size Chart
Here is the business envelope size chart:
| Envelope Type | Size (inches) | Size (mm) | Size (cm) | Size (pixels @96 DPI) | Paper Size It Holds | Common Use | Mails As |
| #6¼ | 3.5 x 6 | 89 x 152 | 8.89 x 15.24 | 336 x 576 | Personal checks, small notes | Compact inserts, cash envelopes | Letter |
| #6¾ | 3.625 x 6.5 | 92 x 165 | 9.21 x 16.51 | 348 x 624 | Personal check (3″ x 6″) | Small inserts, payments | Letter |
| #7 | 3.75 x 6.75 | 95 x 171 | 9.52 x 17.15 | 360 x 648 | Small folded stationery | Short letters, notes | Letter |
| #8⅝ | 3.625 x 8.625 | 92 x 219 | 9.21 x 21.91 | 348 x 828 | Slips, checks | Financial documents | Letter |
| #9 (Regular) | 3.875 x 8.875 | 98 x 225 | 9.84 x 22.54 | 372 x 852 | Fits into #10 envelope (⅓ of 8.5″ x 11″) | Return envelopes, reply mail | Letter |
| #9 (Policy) | 4 x 9 | 102 x 229 | 10.16 x 22.86 | 384 x 864 | One-third folded sheets | Official correspondence, enclosures | Letter |
| #10 (Regular) | 4.125 x 9.5 | 105 x 241 | 10.48 x 24.13 | 396 x 912 | 8.5″ x 11″ tri-folded | Standard business correspondence | Letter |
| #10 (Policy) | 4.125 x 9.5 | 105 x 241 | 10.48 x 24.13 | 396 x 912 | 8.5″ x 11″ tri-folded | Vertical opening for documents | Letter |
| #11 | 4.5 x 10.375 | 114 x 264 | 11.43 x 26.35 | 432 x 996 | Multiple folded sheets | Promotional or legal mailings | Letter |
| #12 | 4.75 x 11 | 121 x 279 | 12.07 x 27.94 | 456 x 1056 | Legal size tri-folded or thick contents | Multi-page statements, contracts | Letter |
| #14 | 5 x 11.5 | 127 x 292 | 12.7 x 29.21 | 480 x 1104 | Bulky or unfolded legal docs | Thick contents, flat mailing | Letter / Flat |
| #16 | 6 x 12 | 152 x 305 | 15.24 x 30.48 | 576 x 1152 | Larger inserts, booklets | Overstuffed or larger mailings | Flat |
Catalog Envelopes
Catalog envelopes are also known as open end envelopes. These types of envelopes are equivalent to mega shopping bags.
That’s because they are big enough to fit anything in them. However, as the name suggests, catalog envelopes are used to keep catalogs as well as magazines and other oversized papers.
The reason for their huge size is that magazines are pretty hard to fold, and doing so would most likely crease them or worse damage them. Therefore, these envelopes keep magazines and other huge pieces safe from that.
More so, their closure is on the smaller side, and their flaps are closed with a tie, a seal sticker, or a clasp, depending on the size of the envelope.
Just like the sizes, the colors of catalog envelopes also vary depending on the pieces needed to fit in them.
Catalog Envelopes Size Chart
The regular envelope size for catalog envelopes is as follows:
| Envelope Type | Size (inches) | Size (mm) | Size (cm) | Size (pixels @96 DPI) | What It Holds | Common Use | Mailing Guidance |
| No. 1 | 6 × 9 | 152 × 229 | 15.24 × 22.86 | 576 × 864 | Half-folded 8.5″ × 11″ sheets or small booklets | Common catalog or document size | Always mails as a flat |
| 1 ¾ | 6.5 × 9.5 | 165 × 241 | 16.51 × 24.13 | 624 × 912 | Slightly larger than #1, fits thicker contents | Used for folded brochures or invoices | Can mail as letter if thin, otherwise flat |
| No. 3 | 7 × 10 | 178 × 254 | 17.78 × 25.4 | 672 × 960 | Letter-size documents folded once | Ideal for reports, statements, or product sheets | Mails as flat if thickness ≤ ¾″ |
| No. 6 | 7.5 × 10.5 | 191 × 267 | 19.05 × 26.67 | 720 × 1008 | Compact catalogs and brochures | Marketing, promotional materials | USPS flat rate if ≤ ¾″ thick |
| No. 8 | 8.25 × 11.25 | 210 × 286 | 20.96 × 28.58 | 792 × 1080 | Half-size magazines or multi-page booklets | Great for marketing packets | Must meet flat-size USPS dimensions |
| 9 ¾ | 8.75 × 11.25 | 222 × 286 | 22.23 × 28.58 | 840 × 1080 | Thick brochures or manuals | For bulkier inserts or multiple-page documents | Flexible flat rate under USPS standards |
| No. 10 ½ | 9 × 12 | 229 × 305 | 22.86 × 30.48 | 864 × 1152 | Full 8.5″ × 11″ sheets flat | Standard for business correspondence | Always considered a flat mailing |
| No. 13 ½ | 10 × 13 | 254 × 330 | 25.4 × 33.02 | 960 × 1248 | Thicker packets, catalogs, presentations | Common in offices for larger documents | Mails as flat if flexible and ≤ ¾″ thick |
| 14 ¼ | 10 × 15 | 254 × 381 | 25.4 × 38.1 | 960 × 1440 | Large documents, booklets, or portfolios | Oversized catalogs or art prints | Considered a flat or large envelope by USPS |
Booklet Envelopes
Booklet envelopes are quite similar to catalog envelopes in terms of size. However, the only difference is that these types of envelopes have a closure on the long side as opposed to the catalog’s smaller side closure.
What this does is it gives booklet envelopes a larger flap that can be closed using sealed stickers.
These envelopes are also called open size envelopes. And just like catalogs, these envelopes are used to mail out oversized documents, and pieces or a few of them in one envelope.
However, they can carry more pieces than catalog envelopes due to their larger closure and nature.
Booklet Envelopes Size Chart
If you are wondering what size is a #10 envelope for booklets, then the size chart for the booklet envelopes, as well as the insert, is as follows:
| Envelope Type | Size (inches) | Size (cm) | Size (pixels @96 DPI) | What It Holds | Mailing Guidance |
| No. 3 | 4.75 × 6.5 | 12.07 × 16.51 | 456 × 624 | Small greeting cards, invitations, or folded notes | Can be mailed as a letter if under ¼″ thick |
| No. 4 ½ | 5.5 × 7.5 | 13.97 × 19.05 | 528 × 720 | Personal notes or inserts | Fits letter-size mailing standards |
| No. 5 | 5.5 × 8.125 | 13.97 × 20.64 | 528 × 780 | Compact catalogs or brochures | Letter-size mail if within USPS limits |
| No. 6 | 5.75 × 8.875 | 14.61 × 22.54 | 552 × 852 | Folded marketing sheets or booklets | Considered letter-size. |
| No. 6 ½ | 6 × 9 | 15.24 × 22.86 | 576 × 864 | Half-folded sheets or small booklets | Classified as a flat. |
| No. 6 ⅝ | 6 × 9.5 | 15.24 × 24.13 | 576 × 912 | Reports or lightweight brochures | Mails as flat rate if flexible |
| No. 6 ¾ | 6.5 × 9.5 | 16.51 × 24.13 | 624 × 912 | Bulkier folded materials or thicker inserts | Considered a flat rate if under ¾″ thick |
| No. 7 ¼ | 7 × 10 | 17.78 × 25.4 | 672 × 960 | Multi-page brochures or packets | Classified as a flat. |
| No. 7 ½ | 7.5 × 10.5 | 19.05 × 26.67 | 720 × 1008 | Medium booklets and corporate reports | Falls under flat-size category |
| No. 9 | 8.75 × 11.5 | 22.20 × 29.21 | 840 × 1104 | Full 8.5″ × 11″ sheets and large reports | Mailed as a flat-size envelope |
| No. 9 ½ | 9 × 12 | 22.86 × 30.48 | 912 × 1152 | Full-size documents, resumes, or certificates | Considered a flat. |
| No. 10 | 9.5 × 12.625 | 24.13 × 32.07 | 912 × 1212 | Professional presentations or document sets | Flat rate if under ¾″ thick |
| No. 13 | 10 × 13 | 25.4 × 33.02 | 960 × 1248 | Catalogs, proposals, or creative portfolios | Flat rate if flexible and under USPS limits |
Coin Envelopes
Ever wondered how people used to send money back in the day, when online transactions didn’t exist, and you had to wire money?
They did so using coin envelopes. Yes, that’s right, a heavy-duty paper envelope strong enough to hold the weight of coins.
More so, these envelopes were used to carry small items like screws, thumbtacks, and various other items. Coin envelopes are used by various industries today for storing different items.
Their sheer heavy-duty nature allows them to hold items with substantial weight without tearing them apart. More so, coin envelopes come in different sizes to meet different kinds of needs as well.
Coin Envelopes Size Chart
The size of coin envelopes, depending on the envelope number, is as follows:
| Envelope Type | Size (inches) | Size (cm) | Size (pixels @96 DPI) | What It Holds | Common Use | Mailing Guidance |
| No. 1 Coin Envelope | 2.25 × 3.5 | 5.7 × 8.9 | 216 × 336 | Coins, stamps, small jewelry pieces | Offices, jewelry stores, collectors | Not suitable for direct mailing; best for secure storage or inclusion inside larger envelopes |
| No. 3 Coin Envelope | 2.5 × 4.25 | 6.35 × 10.8 | 240 × 408 | Keys, pins, small hardware | Workshops, craft stores, office organization | Too small for standalone mailing; can be enclosed in larger mailers |
| No. 4 Coin Envelope | 3 × 4.5 | 7.6 × 11.4 | 288 × 432 | Coins, folded notes, small tokens | Retail, schools, administrative use | Not USPS-approved for mailing; best used for sorting and labeling items |
| No. 5 Coin Envelope | 2.875 × 5.25 | 7.3 × 13.3 | 276 × 504 | Folded receipts, checks, cards | Offices, banks, payment handling | Too compact for mailing; use as an insert or hand delivery |
| No. 6 Coin Envelope | 3.625 × 6 | 9.2 × 15.2 | 348 × 576 | Small documents, business cards | Business correspondence, event tokens | May fit in larger mailers; not suitable for independent postal mailing |
| Mini-lope | 3.625 × 2.125 | 9.2 × 5.4 | 348 × 204 | Gift tags, notes, decorative cards | Gift packaging, crafts, invitations | Not for mailing; decorative or internal packaging use only |
Security Tinted and Window Envelopes
These days, there are not many safe ways to send paper mail. However, there is one secure way to send sensitive information by mail.
And that is through using security tinted and window envelopes. These types of envelopes are used by banks, hospitals, and companies.
They use tined envelopes to deliver documents like financial documents, personal and medical information, and bank checks.
Security tinted envelopes offer added privacy with windows. This helps provide a clear view of the delivery address.
By doing so, it makes sure the envelope is delivered to the right address and not the wrong one. However, you must make sure you know how to address business envelopes. More so, these types of envelopes come in standard sizes.
The security tinted standard size envelopes feature a single window. However, it also comes with double windows. That way, you can choose the envelope you like the best for your needs.
Security Tinted and Window Envelopes Size Chart
If you’re wondering what size is a legal envelope, then the return envelope size chart for security tinted and window envelopes is as follows:
| Envelope Type | Size (inches) | Size (cm) | Size (pixels @96 DPI) | What It Holds | Common Use | Mailing Guidance |
| #6 ¾ Security Tinted Envelope | 3.625 × 6.5 | 9.21 × 16.51 | 348 × 624 | Checks, small letters, invoices | Financial institutions, personal correspondence | Mailable as a standard letter if under ¼” thick |
| #8 ⅝ Security Tinted Envelope | 3.625 × 8.625 | 9.21 × 21.91 | 348 × 828 | Slim folded statements or receipts | Office billing, transaction confirmations | Meets USPS letter-size standards |
| #9 Security Tinted Envelope | 3.875 × 8.875 | 9.84 × 22.54 | 372 × 852 | Standard business correspondence | Banks, insurance companies, legal documents | Common return envelope size; fits inside #10 envelope |
| #10 Security Tinted Envelope | 4.125 × 9.5 | 10.48 × 24.13 | 396 × 912 | Standard 8.5″ × 11″ sheets folded in thirds | Business letters, invoices, marketing mail | USPS letter-size compliant; ideal for bulk mailing |
| #9 Single Window Envelope | 3.875 × 8.875 | 9.84 × 22.54 | 372 × 852 | Invoices, statements with address alignment | Corporate billing, automated mailing | Window must clearly show address to meet USPS standards |
| #10 Single Window Envelope | 4.125 × 9.5 | 10.48 × 24.13 | 396 × 912 | Business letters with printed address | Payroll, statements, invoices | Must display address fully; letter-size compatible |
| #10 Double Window Envelope | 4.125 × 9.5 | 10.48 × 24.13 | 396 × 912 | Documents with printed sender & receiver info | Accounting, HR, and finance mailings | Align both windows properly; fits standard letter folds |
| #11 Security Tinted Envelope | 4.5 × 10.375 | 11.43 × 26.35 | 432 × 996 | Contracts, large statements | Corporate or legal correspondence | Flat-rate letter category if within thickness limit |
| #12 Window Envelope | 4.75 × 11 | 12.07 × 27.94 | 456 × 1056 | Legal-sized folded documents | Financial institutions, utility companies | Must meet USPS clear window visibility requirements |
Announcement Envelopes
Announcement envelopes, as the name suggests, are used for celebration purposes. They are A-style sizes and used for cards, photos, and event announcements.
More so, they are used for official purposes, like any company announcements that need to stand out with a polished presentation.
As for the size chart of announcement envelopes, it is as follows:
| Envelope Type | Size (inches) | Size (cm) | Size (pixels @96 DPI) | What It Holds | Common Use | Mailing Guidance |
| A1 | 3.625 × 5.125 | 9.21 × 13.02 | 348 × 492 | RSVP cards, small thank-you notes | Weddings, event invitations | Mails as a letter if within USPS size and weight limits |
| A2 | 4.375 × 5.75 | 11.11 × 14.61 | 420 × 552 | 4.25″ × 5.5″ cards | Greeting cards, small invitations | Standard letter-size mail; ideal for personal stationery |
| A6 | 4.75 × 6.5 | 12.07 × 16.51 | 456 × 624 | 4″ × 6″ photos or postcards | Photo prints, announcements | Standard letter category if under ¼″ thick |
| A7 | 5.25 × 7.25 | 13.34 × 18.42 | 504 × 696 | 5″ × 7″ cards or invites | Formal invitations, holiday cards | Most popular invite size; USPS letter-size eligible |
| A8 | 5.5 × 8.125 | 13.97 × 20.64 | 528 × 780 | 5″ × 8″ inserts or folded stationery | Event programs, premium invitations | USPS letter if under 3.5 oz; otherwise non-machinable |
| A9 | 5.75 × 8.75 | 14.61 × 22.23 | 552 × 840 | 5.5″ × 8.5″ inserts or marketing cards | Announcements, photo mailers | Slightly oversized; can incur non-machinable surcharge |
| A10 | 6 × 9.5 | 15.24 × 24.13 | 576 × 912 | 6″ × 9″ announcements or brochures | Invitations with multiple inserts | Mails as a flat due to larger size |
| Square (e.g., 6.5″ × 6.5″) | 6.5 × 6.5 | 16.51 × 16.51 | 624 × 624 | Square greeting or wedding cards | Modern, creative invites | Non-machinable surcharge applies to all square envelopes |
Invitation Envelopes
While invitation envelopes can get confused with announcement envelopes, they are not the same thing.
Invitation envelopes are used for invitation purposes, whether it is an invitation to a wedding, a birthday party, or any occasion for that matter. They are A-style and square format.
This makes them the best for event invitations. Furthermore, they have thick paper and an aesthetic appeal to them. This makes invitations meaningful before they are opened.
Invitation Envelopes Size Chart
The invitation envelope size chart is as follows:
| Envelope Type | Size (inches) | Size (cm) | Size (pixels @96 DPI) | What It Holds | Common Use | Mailing Guidance |
| A2 | 4.375 × 5.75 | 11.11 × 14.61 | 420 × 552 | 4.25″ × 5.5″ RSVP or note cards | Small thank-you notes, RSVP cards, mini invites | Standard letter-size if under USPS weight limits |
| A6 | 4.75 × 6.5 | 12.07 × 16.51 | 456 × 624 | 4″ × 6″ photos or flat cards | Save-the-dates, invitations, or photo cards | Mails as letter-size if ≤¼″ thick |
| A7 | 5.25 × 7.25 | 13.34 × 18.42 | 504 × 696 | 5″ × 7″ invitation cards | The most popular size for weddings or events | Standard letter mail; eligible for machine processing |
| A8 | 5.5 × 8.125 | 13.97 × 20.64 | 528 × 780 | 5″ × 8″ invitations or folded cards | Elegant event programs, large invites | USPS letter-size if within limits; otherwise surcharge applies |
| A9 | 5.75 × 8.75 | 14.61 × 22.23 | 552 × 840 | 5.5″ × 8.5″ invitation suites | Layered or luxury invitations | May qualify as non-machinable if heavier or rigid |
| A10 | 6 × 9.5 | 15.24 × 24.13 | 576 × 912 | 6″ × 9″ multi-piece invitation sets | Premium or oversized invitations | Mails as a flat due to larger dimensions |
| Square (e.g., 6.5 × 6.5) | 6.5 × 6.5 | 16.51 × 16.51 | 624 × 624 | Square cards and invitations | Creative, modern invitation formats | Non-machinable surcharge applies to all square envelopes |
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Baronial Envelopes
Baronial envelopes are traditional and stylish envelopes. These are used for formal invitations and as greeting cards.
More so, they feature a deep, pointed flap that gives off aesthetic vibes and makes them look great. They are also used for weddings, ceremonies, or other occasions.
Baronial Envelopes Size Chart
The size chart for Baronial envelopes is as follows:
| Envelope Type | Size (inches) | Size (cm) | Size (pixels @96 DPI) | What It Holds | Common Use | Mailing Guidance |
| 1 Bar / No. 4 / 4-Bar | 3.625 × 5.125 | 9.21 × 13.02 | 348 × 492 | 3.5″ × 5″ RSVP or note cards | Used for RSVP cards and personal stationery | Mails as a letter if under ¼″ thick |
| No. 5 / 5-Bar | 4.125 × 5.5 | 10.48 × 13.97 | 396 × 528 | 4″ × 5.25″ folded cards | Greeting cards, small announcements | Standard letter-size if within weight limits |
| No. 5½ / 5½-Bar | 4.375 × 5.75 | 11.11 × 14.61 | 420 × 552 | 4.25″ × 5.5″ cards | Invitations and thank-you notes | Eligible for letter postage if flexible |
| No. 6 / 6-Bar | 4.75 × 6.5 | 12.07 × 16.51 | 456 × 624 | 4.5″ × 6.25″ cards | Popular for wedding enclosures and photo cards | Mails as letter-size if ≤¼″ thick |
| No. 7 / 7-Bar | 5.25 × 7.25 | 13.34 × 18.42 | 504 × 696 | 5″ × 7″ invitations or greeting cards | The most common baronial envelope for formal invitations | Standard letter; surcharge if rigid or square |
| #7 (Monarch) | 3.875 × 7.5 | 9.84 × 19.05 | 372 × 720 | 3.75″ × 7.25″ correspondence sheets | Personal or business stationery | Mails as a letter within size and weight limits |
| Lee | 5.25 × 7.25 | 13.34 × 18.42 | 504 × 696 | 5″ × 7″ inserts or announcements | Elegant invitation or stationery use | Standard letter mail rate |
| No. 8 / 8-Bar | 5.5 × 8.125 | 13.97 × 20.64 | 528 × 780 | 5.25″ × 7.75″ invites or photo cards | For larger formal invitations | May qualify as non-machinable if thicker |
| No. 9 / 9-Bar | 5.75 × 8.75 | 14.61 × 22.23 | 552 × 840 | 5.5″ × 8.5″ cards or layered invitations | Wedding suites and event invites | Letter-size if flexible; surcharge if rigid |
| No. 10 / 10-Bar | 6 × 9.5 | 15.24 × 24.13 | 576 × 912 | 6″ × 9″ large cards or invitation sets | Premium invitation suites or programs | Considered a flat by USPS due to larger size |
Square Envelopes
Square envelopes are a bit of a different take on the standard rectangular envelope shapes. These envelopes stand out for their unique and symmetrical design, which looks great.
More so, square envelopes are used for invitations, promotional inserts, and artistic mailings. Their visual appeal adds creativity and charm. However, they require extra postage due to non-machinable dimensions.
Square Envelopes Size Chart
The size chart for square envelopes is as follows:
| Envelope Type | Size (inches) | Size (cm) | Size (pixels @96 DPI) | What It Holds | Mailing Guidance |
| No. 5 | 5 × 5 | 12.7 × 12.7 | 480 × 480 | Small square cards or mini invites | Mails as non-machinable letter (extra postage |
| No. 5½ | 5.5 × 5.5 | 13.97 × 13.97 | 528 × 528 | 5.25″ × 5.25″ cards | Non-machinable surcharge applies |
| No. 6 | 6 × 6 | 15.24 × 15.24 | 576 × 576 | 5.75″ × 5.75″ cards | Mails as flat if thick, or non-machinable letter |
| No. 6½ | 6.5 × 6.5 | 16.51 × 16.51 | 624 × 624 | 6.25″ × 6.25″ invitations | Extra postage required for non-machinable shape |
| No. 7 | 7 × 7 | 17.78 × 17.78 | 672 × 672 | 6.75″ × 6.75″ inserts | Considered non-machinable by USPS |
| No. 7½ | 7.5 × 7.5 | 19.05 × 19.05 | 720 × 720 | 7.25″ × 7.25″ cards | Mails as a flat or large letter with surcharge |
| No. 8 | 8 × 8 | 20.32 × 20.32 | 768 × 768 | 7.75″ × 7.75″ booklets or artwork | Non-machinable letter or flat, depending on weight |
| No. 8½ | 8.5 × 8.5 | 21.59 × 21.59 | 816 × 816 | 8″ × 8″ materials | Always non-machinable; extra postage required |
| No. 9 | 9 × 9 | 22.86 × 22.86 | 864 × 864 | 8.75″ × 8.75″ inserts | Flat-size mailing with surcharge |
| No. 9½ | 9.5 × 9.5 | 24.13 × 24.13 | 912 × 912 | 9″ × 9″ square cards | Flat rate if flexible and ≤¾″ thick |
| No. 10 | 10 × 10 | 25.4 × 25.4 | 960 × 960 | 9.75″ × 9.75″ cards or booklets | Mails as a flat with extra postage |
| No. 13½ | 13.5 × 13.5 | 34.29 × 34.29 | 1296 × 1296 | Large artwork or presentation sheets | Always flat-size; additional postage required |
Remittance Envelopes
Remittance envelopes are quite useful options for donations, payments, and business transactions.
These envelopes have a flap or form inside for collecting personal or billing information. More so, they are used for charity purposes and by schools.
These envelopes are used to store money or checks securely. As for the size chart for remittance envelopes, it is as follows:
| Envelope Type | Size (inches) | Size (cm) | Size (pixels @96 DPI) | What It Holds | Common Use | Mailing Guidance |
| #6 ¼ Remittance | 3.5 x 6 | 8.89 x 15.24 | 336 x 576 | Small donation slips, folded letters, or compact forms. | Ideal for churches, nonprofits, and small fundraising campaigns. | Fits neatly in standard collection boxes or return mailers. Use lightweight paper to avoid bulk. |
| #6 ½ Remittance | 3.5 x 6.25 | 8.89 x 15.875 | 336 x 600 | Shorter correspondence, folded receipts, or reply forms. | Commonly used for payment collection or event ticket responses. | Best for including pre-printed address and perforated reply sections for efficiency. |
| #6 ¾ Remittance | 3.625 x 6.5 | 9.21 x 16.51 | 348 x 624 | Small inserts, folded checks, or contribution slips. | Popular for mailed donations and return envelopes in billing statements. | Ensure the contents fit snugly; avoid overstuffing to maintain envelope seal integrity. |
| #9 Remittance | 3.875 x 8.875 | 9.84 x 22.54 | 372 x 852 | Folded 8.5” x 11” sheets, donation cards, or return forms. | Used by charities, utilities, and membership organizations for larger reply mail. | Meets USPS standards for letter-size mail; use standard postage and secure closures for bulk mailing. |
Other Protective Mailers and Their Sizes
There are two more types of mailers. And even though they are not traditional “envelopes,” they are still used for packaging and shipping. These two mailers and their size charts are as follows:
Padded Mailers
While padded mailers are used for mailing purposes and used as an alternative to envelopes, they are not traditional “envelopes,” as per se.
From a technical standpoint, they belong to a category of protective mailing supplies or shipping envelopes.
These are used for packaging and shipping rather than simple correspondence. However, in the mailing industry context, they are still grouped under “envelope types” for convenience.
These envelopes or mailers, should I say, feature soft cushioning inside made of recycled paper, tissue, or foam to protect fragile items during shipping.
They are used for shipping small electronics, books, and small accessories so that they arrive safely and without any damage.
Padded Mailers Size Chart
The size chart for the padded mailer is as follows:
| Envelope Type | Size (inches) | Size (cm) | Size (pixels @96 DPI) | What It Holds | Mailing Guidance |
| #000 Padded Mailer | 4 x 8 | 10.16 x 20.32 | 384 x 768 | Small jewelry, USB drives, keys, or SD cards. | Use for lightweight products under 4 oz. |
| #00 Padded Mailer | 5 x 10 | 12.7 x 25.4 | 480 x 960 | Cables, pens, or cosmetic samples. | Keep item thickness under ¾ inch to qualify for First-Class Package rates. |
| #0 Padded Mailer | 6 x 9 | 15.24 x 22.86 | 576 x 864 | Small electronics, flash drives, or greeting cards. | Avoid overstuffing as it can damage the bubble lining. |
| #1 Padded Mailer | 7.25 x 12 | 18.42 x 30.48 | 696 x 1,152 | Books, DVDs, or phone cases. | Meets USPS parcel mail dimensions; add a fragile sticker for extra care. |
| #2 Padded Mailer | 8.5 x 12 | 21.59 x 30.48 | 816 x 1,152 | Small apparel, notebooks, or accessories. | Avoid folding rigid items; pad additional fragile products inside. |
| #3 Padded Mailer | 8.5 x 14.5 | 21.59 x 36.83 | 816 x 1,392 | Calendars, magazines, or catalogs. | Tape edges for extra security if the envelope feels full. |
| #4 Padded Mailer | 9.5 x 14.5 | 24.13 x 36.83 | 912 x 1,392 | Larger books, tech gadgets, or thick documents. | May qualify as a flat or parcel depending on thickness. |
| #5 Padded Mailer | 10.5 x 16 | 26.67 x 40.64 | 1,008 x 1,536 | Clothing, photo albums, or small product boxes. | Secure with reinforced tape for heavier items over 1 lb. |
| #6 Padded Mailer | 12.5 x 19 | 31.75 x 48.26 | 1,200 x 1,824 | Large documents, tablets, or framed photos. | Avoid bending; consider double padding for fragile electronics. |
| #7 Padded Mailer | 14.25 x 20 | 36.2 x 50.8 | 1,368 x 1,920 | Jackets, shoes, or large boxed products. | Use printed labels for clarity. |
Bubble Mailers
Bubble mailers are just like padded mailers except they have a plastic bubble wrap lining inside for extra cushioning, which the padded mailers do not.
These mailers are lined with bubble wrap. More so, they are also used for shipping fragile items with protection so that they do not scratch or bend.
Bubble mailers offer protection with convenience and keep items secure during shipping.
Bubble Mailers Size Chart
The size chart for bubble mailers is as follows:
| Envelope Type | Size (inches) | Size (cm) | Size (pixels @96 DPI) | What It Holds | Mailing Guidance |
| #000 Bubble Mailer | 4 x 8 | 10.16 x 20.32 | 384 x 768 | Jewelry, SD cards, USB drives, or keys. | Ideal for lightweight shipments under 4 oz; qualifies for USPS First-Class Package. |
| #00 Bubble Mailer | 5 x 10 | 12.7 x 25.4 | 480 x 960 | Small accessories, pens, or watch straps. | Ensure contents are flat; avoid overpacking to maintain envelope integrity. |
| #0 Bubble Mailer | 6 x 9 | 15.24 x 22.86 | 576 x 864 | Greeting cards, flash drives, or small gadgets. | Meets USPS parcel requirements; seal securely for added protection. |
| #1 Bubble Mailer | 7.25 x 12 | 18.42 x 30.48 | 696 x 1,152 | Books, small electronics, or phone accessories. | Add fragile or “Do Not Bend” labels for sensitive products. |
| #2 Bubble Mailer | 8.5 x 12 | 21.59 x 30.48 | 816 x 1,152 | Apparel, notebooks, or small boxes. | Use additional padding for items with sharp edges. |
| #3 Bubble Mailer | 8.5 x 14.5 | 21.59 x 36.83 | 816 x 1,392 | Calendars, books, or magazines. | Flatten contents evenly to avoid bulging; reinforce seams if needed. |
| #4 Bubble Mailer | 9.5 x 14.5 | 24.13 x 36.83 | 912 x 1,392 | Laptops, thick documents, or tech gear. | Tape edges for secure closure; may qualify as parcel mail. |
| #5 Bubble Mailer | 10.5 x 16 | 26.67 x 40.64 | 1,008 x 1,536 | Larger apparel, photo books, or electronics. | Avoid folding or compressing; maintain flat surface for scanning labels. |
| #6 Bubble Mailer | 12.5 x 19 | 31.75 x 48.26 | 1,200 x 1,824 | Tablets, framed photos, or thick catalogs. | Consider double-padding for fragile glass or screen items. |
| #7 Bubble Mailer | 14.25 x 20 | 36.2 x 50.8 | 1,368 x 1,920 | Shoes, jackets, or boxed goods. | Ensure even weight distribution; may require parcel-rate postage due to size. |
How to Choose the Right Business Envelope
Using the right business envelope sizes as well as envelope types is key to sending items safely. You want to use the right envelope for the things you are enveloping.
After all, the goal is to send things in a way that looks clean and, more importantly, arrives without issues. An envelope too big or too small is a no go.
However, before picking the business envelope size or type, for that matter, it comes down to knowing these three things.
First, what is it that you’re sending, and secondly, how it should arrive, and lastly, what it’ll cost to mail. For most purposes and day-to-day mail, #10 business size envelopes will do.
The business envelope examples handle the everyday stuff, like sending letters, and can be printed easily. More so, envelope #10 size follows standard postage and USPS size rules and is machine-readable.
However, if you have documents that can’t be folded like a letter, for instance, you will need to use a flat envelope like 9×12 or 10×13. This will keep the content unfolded and crisp so that you do not have to worry about any creases.
However, if you want your mail to look visually appealing, then for the best designs, you can go with A-style or square envelopes.
Keep in mind that square envelopes cost more to ship. For large items, you will need to use catalog envelopes that fall under parcel pricing.
However, you must know the size of the content and match the envelope to its size. Only then will you be able to choose the right envelope.
Also, you must know the minimums and maximums for what size is a business envelope. The smallest envelope you can go with measures 3.5” x 5”. As for the largest, it measures 6.125” x 11.5”.
Why Should You Use Business Envelopes?
There is nothing more telling than handing out an envelope containing what seems to be a pretty important business document.
And that feeling of importance can never be replaced by sending out an email. But that is not all, as there are a handful of other benefits to using business envelopes.
Envelopes play their fair share of roles in making the first impression on the recipient. Depending on the design of an envelope, that impression can be a good one or a not-so-good one.
That is why the design of business envelopes must be spot on. After all, the fate of the content in it depends on it. That’s the fate of whether the receiver opens the envelope and checks out what’s in it.
Or, whether they throw away the whole thing onto a pile of office papers. It’s safe to say everything depends on the envelope.
Therefore, when it comes to setting up your business communications, business envelope design is the first thing you must start with.
It is your responsibility as a business owner to make sure that your business envelope design influences the receiver into making the right decision. This will be beneficial for your business’ success in the long run.
That being said, below are some more reasons why you should use business envelopes:
Keep the Classic Essence Intact
If you have been living under a rock, then you should know that envelopes have always been the way of delivering documents.
But more so, they evoke a feeling that is reminiscent of the old times. It’s a gesture that feels more personal.
And that means a lot in a time when everything is sent through emails and text messages. Therefore, receiving a paper envelope creates an experience that feels real, something an email can’t do.
On top of that, it keeps intact the timeless traditions of professionalism and formality. This essence is what emails, or any other tech for that matter, lack.
Envelopes, especially the ones printed with a logo or address, point out that the stuff inside is official and important.
Simply put, envelopes maintain the classic essence of business etiquette. They are a standard of credibility that has existed for so many decades.
Stand Out From Your Competitors
The world of business is getting crowded and crowded as the days go on. That is why you must make your business stand out from the crowd.
For that, you will need to be on the front foot and always think of ways your company can improve its offerings.
More so, your company must provide better value than the competition. But if there’s one area where you can truly get an advantage over your competitors, it’s by nailing your business card design.
While others will overlook business envelopes with logos, thinking of them as unimportant thing, you should not take them lightly.
Remember, every business inquiry or dealing starts with some paperwork, which more often or not is delivered in an envelope.
And like all things in business, the first impression is the last impression. So, make it count with your business envelopes.
Make It Your Brand’s Signature
Every company has some sort of signature that is unique and synonymous with its brand image. Custom business envelopes reflect your company’s brand identity and attention to detail.
More so, they convey a very bold message that your company is all about legacy. Building a brand reputation and having a signature is what businesses strive for.
So, an envelope that is designed to a T gives you the chance to make it your brand’s signature. Not only will it help you stand out from others, but it will also make your brand instantly recognizable as soon as someone sees your business envelope.
Remember the Hogwarts envelope with the Hogwarts crest on top and a red seal containing the Hogwarts acceptance letter inside? As soon as a lucky receiver saw the envelope, they were thrilled and full of joy.
More so, they knew right away that something special was in store inside the envelope. So, just like that Hogwarts envelope, you can make your business envelope just as iconic.
And how do you do that? Well, when you make it your brand’s signature, the envelope becomes instantly recognizable.
And just like the young wizards and witches, your clients can also be over the moon by just seeing your envelope.
Enhance Connections and Boost Engagement
While sending papers and documents is the main point of your business communications, the manner in which you send them should also matter.
And the manner of delivering via envelopes forges a bond with your clients. By just using printed business envelopes to deliver papers to clients, you enhance their experience.
More so, you improve the client’s connection with the brand as well. Also, an envelope that looks spot on in terms of design is more likely to be opened by a person compared to just letters without any design.
Get Your Envelopes Opened and Noticed
Let Our Team Make Your Envelope Stand Out
Look Professional
Envelopes make your company look professional; it is as simple as that. Personalized business envelopes send out one clear message: that your company knows its stuff and knows how to do it right.
While many companies look to impress clients, they somehow overlook a tiny detail. And that detail is an envelope.
However, in the bigger picture, this small detail is what leads firms to greater things. As you know, nothing is more important for a company than to look professional.
Every company wants to look credible and trustworthy. After all, these three things are what determine a company’s position in the market.
So, when a company uses an envelope, it sets the tone of professionalism right away. It lets the customer know that you mean business and take things seriously, long before they open the envelope and find out what’s inside it.
Get Started With Webnhubs for Your Business Envelope Design
As we have covered throughout this blog, it is all about choosing the right business envelope size and making your business envelope design look spot-on.
So when it comes to choosing the business envelope size and designing business envelopes, there are not many design agencies that can do a better job than Webnhubs.
Webnhubs is a full-on design firm that has a team of skilled and creative designers. They offer Envelope Design Services for businesses looking to stand out from the competition with their envelopes.
We know the design trends, and we know what’s in and what’s not. That is why we will design a business envelope that looks modern and professional.
We want your business envelope design as well as the size of business envelope to impress your clients so that when they see it, it makes them want to open it right away.
So, partner with Webnhubs and design an envelope that takes your mail delivery experience to a whole new level.
Closing It
That is all, folks! Much like an envelope, we will now wrap this blog up. We hope that the business envelope size, as well as the types of envelopes we featured in this blog, can help you choose the right business envelope size. As we mentioned, your business envelope is an extension of your business and must reflect your brand image in every way.
That is why both the business envelope size and its design need to be perfect at all costs. And if you need someone to design your business envelope, then you can consider Webnhubs for the job. Our team is an expert at designing envelopes and choosing the right business envelope size. More so, we have the skills and experience to back it up. So, what are you waiting for? Design your business envelope with Webnhubs and start mailing papers.
Frequently Asked Questions
The standard business envelope size of the #10 measures 4⅛ inches by 9½ inches, which is equivalent to 10.5 cm by 24.1 cm
A business size envelope is a standard mailing envelope used for business correspondence, with common sizes including the #10. People use these envelopes for mailing letters and documents like invoices, statements, and reports for return or reply mail.
You should use the #10 envelope. It is the standard envelope size for letters, invoices, and statements that you can fold into thirds.
The business envelope is the best type of envelope, specifically the #10 envelope. Everyone uses this envelope as it stores letters and documents that fold into thirds. More so, the #10 business envelopes follow standard postage size rules and are machine-readable.
Sultan Hanif is a seasoned wordsmith, who brings technology trends and innovations to life through his words. A tech-savvy gamer with a passion for all things football, Sultan blends his technical knowledge with creative storytelling to empower businesses and individuals alike.
