American Envelope Sizes

There are dozens of sizes of envelopes available. Not all are used for posting mail, but for such things as former pay packets or putting a gift card or a key in.

Announcement Envelope Sizes

Name	Size in millimeters	Size in inches
A-2	111 mm x 146 mm	4 3/8 in x 5 3/4 in
A-6	120 mm x 165 mm	4 3/4 in x 6 1/2 in
A-7	139 mm x 184 mm	5 1/4 in x 7 1/4 in
A-8	139 mm x 206 mm	5 1/2 in x 8 1/8 in
A-10	159 mm x 244 mm	6 1/4 in x 9 5/8 in
Slim	98 mm x 225 mm	3 7/8 in x 8 7/8 in

Announcement envelopes are very common envelopes and are used for cards and invitations.

Commercial Envelope Sizes

Name	Size in millimeters	Size in inches
No. 6¼	89 mm x 152 mm	3 1/2 in x 6 in
No. 6¾	92 mm x 165 mm	3 5/8 in x 6 1/2 in
No. 8	98 mm x 190 mm	3 7/8 in x 7 1/2 in
No. 9	98 mm x 225 mm	3 7/8 in x 8 7/8 in
No. 10	105 mm x 241 mm	4 1/8 in x 9 1/2 in
No. 11	114 mm x 263 mm	4 1/2 in x 10 3/8 in
No. 12	120 mm x 279 mm	4 3/4 in x 11 in
No. 14	127 mm x 292 mm	5 in x 11 1/2 in

Commercial envelopes are standard-sized envelopes that are used daily for regular mail.

Catalog Envelope Sizes

Name	Size in millimeters	Size in inches
No. 1	152 mm x 228 mm	6 in x 9 in
No. 1¾	165 mm x 241 mm	6 1/2 in x 9 1/2 in
No. 2	165 mm x 254 mm	6 1/2 in x 10 in
No. 3	178 mm x 254 mm	7 in x 10 in
No. 6	190 mm x 266 mm	7 1/2 in x 10 1/2 in
No. 7	203 mm x 279 mm	8 in x 11 in
No. 8	209 mm x 286 mm	8 1/4 in x 11 1/4 in
No. 9½	216 mm x 267 mm	8 1/2 in x 10 1/2 in
No. 9¾	222 mm x 286 mm	8 3/4 in x 11 1/4 in
No. 10½	229 mm x 305 mm	9 in x 12 in
No. 12½	241 mm x 317 mm	9 1/2 in x 12 1/2 in
No. 13½	254 mm x 330 mm	10 in x 13 in
No. 14¼	286 mm x 311 mm	11 1/4 in x 12 1/4 in
No. 14½	292 mm x 368 mm	11 1/2 in x 14 1/2 in

The catalog formats are mostly used for — you saw this one coming — catalogs, folders, flyers and magazines.

Using standard envelop sizes for your work is a logical step, envelopes are availlable in a wide variety of dimensions and having custom envelopes made is possible, but expensive.