There are various types of envelopes that can give a pleasant experience of opening a mail. Here is a size chart which has the ten most commonly used standard envelope sizes.
An envelope gives the first impression of what is inside a mail. Hence, it becomes imperative to choose the most suitable size and shape of the envelope according to its enclosed mail. Moreover, it should not violate the standards prescribed by the postage department. To help you become familiar, here is a complete collection of 10 envelope sizes in the form of a chart. This chart shall provide a complete round up of not only its sizes, but also a brief on its usage and looks.
Envelopes: Size Chart
Commercial
This is the most commonly used, standard business correspondence and direct mail envelope. It includes the widely used standard number 10 envelope.
Square Type
This may not be considered a legal envelope size in some places, but is used these days for special purposes. This may require extra postage charges to mail.
Wallet Flap
Mostly used for bank and financial statements, and confidential documents that need a more secure envelope for extra protection.
Side Seam
This type of envelope is ideally used when you need any kind of machine insertion.
Policy
This is used to safely store or transfer insurance polices, bonds, mortgages and legal papers.
Standard sizes for Commercial, Square Type, Wallet Flap, Side Seam, Side Seam envelopes
| Size | Dimension | Enclosure |
| 6 ¼ | 3.5″ X 6″ | 3.25″ X 5.75″ |
| 6 ¾ | 3.625″ X 6.5″ | 3.5″ X 6.25″ |
| 8 5/8 | 3.625″ X 8.625″ | 3.5″ X 8.375″ |
| Monarch (7 ¾) | 3.875″ X 7.5″ | 3.75″ X 7.25″ |
| 9 (policy) | 4″ X 9″ | 3.75″ X 8.5″ |
| 10 | 4.125″ X 9.5″ | 4″ X 9.25″ |
| DL | 4.313″ X 8.625″ | 4.125″ X 8.375″ |
| 11 | 4.5″ X 10.375″ | 4.25″ X 10.125″ |
| 12 | 4.75″ X 11″ | 4.5″ X 10.75″ |
| 14 | 5″ X 11.5″ | 4.75″ X 11.25″ |
| 16 | 6″ X 12″ | 5.75″ X 11.75″ |
Booklet
It has sides with openings that allow the envelope for overall printing. May also be used for booklets, catalogs, folders and more.
Metal Clasp
It is similar to the catalog style in size and looks, but has a metal clasp which allows multiple openings and closing.
Catalog
It is a large sized envelope used for catalogs magazines, folders, reports and more.
Standard sizes for Booklet, Metal Clasp, Catalog envelopes
| Size | Dimension | Enclosure |
| 3 | 4.75″ X 6.5″ | 4.5″ X 6″ |
| 4 1/2 | 5.5″ X 7.5″ | 5.25″ X 7″ |
| 5 | 5.5″ X 8.125″ | 5.25″ X 7.625″ |
| 6 | 5.75″ X 8.875″ | 5.5″ X 8.375″ |
| 6 1/2 | 6″ X 9″ | 5.75″ X 8.5″ |
| 6 5/8 | 6″ X 9.5″ | 5.75″ X 9″ |
| 6 3/4 | 6.5″ X 9.5″ | 6.25″ X 9″ |
| 7 1/4 | 7″ X 10″ | 6.75″ X 9.5″ |
| 7 1/2 | 7.5″ X 10.5″ | 7.25″ X 10″ |
| 9 | 8.75″ X 11.5″ | 8.5″ X 11″ |
| 9 1/2 | 9″ X 12″ | 8.75″ X 11.5″ |
| 10 | 9.5″ X 12.625″ | 9.25″ X 12.125″ |
| 13 | 10″ X 13″ | 9.75″ X 12.5″ |
Window Type
This is an opening to show the name and address on enclosure. Mostly used for invoices, statements, paychecks, receipts, and more
Standard sizes for Window Type envelopes
| Size | Dimension | Enclosure |
| 6 1/4 | 6″ X 3.5″ | 5.75″ X 3.25″ |
| 6 3/4 | 6.5″ X 3.625″ | 6.25″ X 3.325″ |
| 7 | 6.75″ X 3.75″ | 6.5″ X 3.5″ |
| 7 3/4 (Monarch) | 7.5″ X 3.875″ | 7.25″ X 3.625″ |
| 8 5/8 (Check) | 8.625″ X 3.625″ | 8.375″ X 3.375″ |
| 9 | 8.875″ X 3.875″ | 8.375″ X 3.375″ |
| 10 | 9.5″ X 4.125″ | 9.25″ X 3.875″ |
| 11 | 10.375″ X 4.5″ | 10.125″ X 4.25″ |
| 12 | 11″ X 4.75″ | 10.75″ X 4.5″ |
| 14 | 11.5″ X 5″ | 11.25″ X 4.5″ |
Announcement
Designed for display using matching text and cover papers, and has deckle-edge flaps. It is ideal for stationery, photographs, greeting cards, small booklets, other display purposes.
Standard sizes for Announcement envelopes
| Size | Dimension | Enclosure |
| A-2 | 4.375″ X 5.75″ | 4.25″ X 5.5″ |
| A-6 | 4.75″ X 6.5″ | 4.625″ X 6.25″ |
| A-7 | 5.25″ X 7.25″ | 5.125″ X 7″ |
| A-8 | 5.5″ X 8.125″ | 5.375″ X 7.875″ |
| A-9 | 5.75″ X 8.75″ | 5.5″ X 8.5″ |
| A-10 | 6″ X 9.5″ | 5.875″ X 9.25″ |
Hope you find this size chart as the best overview you can get on various envelopes available and what they can be used for.