US Envelope Paper Sizes

Further Information

There are dozens of sizes of envelopes available. The designations such as 'A2' do not correspond to ISO paper sizes. (Often, North American paper jobbers and printers will insert a hyphen to distinguish from ISO sizes, thus: A-2.). Envelopes accepted by the U.S. Postal Service to be eligible for mailing at the price for letters must be rectangular and at least  3 1/2 inches high × 5 inches long × 0.007 inch thick.

Source: Wikipedia

Format Width x Height (mm) Width x Height (in)
152.4 x 88.9 mm 6 x 3.5 in
165.1 x 92.1 mm 6.5 x 3.6 in
7 171.5 x 95.3 mm 6.8 x 3.8 in
7¾ Monarch 190.5 x 98.4 mm 7.5 x 3.9 in
8⅝ 219.1 x 92.1 mm 8.6 x 3.6 in
9 225.4 x 98.4 mm 8.9 x 3.9 in
10 241.3 x 104.8 mm 9.5 x 4.1 in
11 263.5 x 114.3 mm 10.4 x 4.5 in
12 279.4 x 120.7 mm 11 x 4.8 in
14 292.1 x 127 mm 11.5 x 5 in
16 304.8 x 152.4 mm 12 x 6 in
A1 92.1 x 130.2 mm 3.6 x 5.1 in
A2 Lady Grey 146.1 x 111.1 mm 5.8 x 4.4 in
A4 158.7 x 108 mm 6.2 x 4.3 in
A6 Thompson's Standard 165.1 x 120.7 mm 6.5 x 4.8 in
A7 Besselheim 184.2 x 133.4 mm 7.3 x 5.3 in
A8 Carr's 206.4 x 139.7 mm 8.1 x 5.5 in
A9 Diplomat 222.3 x 146.1 mm 8.8 x 5.8 in
A10 Willow 241.3 x 152.4 mm 9.5 x 6 in
A Long 225.4 x 98.4 mm 8.9 x 3.9 in
1 228.6 x 152.4 mm 9 x 6 in
241.3 x 152.4 mm 9.5 x 6 in
3 254 x 177.8 mm 10 x 7 in
6 1266.7 x 190.5 mm 49.9 x 7.5 in
8 285.8 x 209.6 mm 11.3 x 8.3 in
285.8 x 222.3 mm 11.3 x 8.8 in
10½ 304.8 x 228.6 mm 12 x 9 in
12½ 317.5 x 241.3 mm 12.5 x 9.5 in
13½ 330.2 x 254 mm 13 x 10 in
14½ 368.3 x 292.1 mm 14.5 x 11.5 in
15 381 x 254 mm 15 x 10 in
15½ 393.7 x 304.8 mm 15.5 x 12 in