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.

Most envelope sizes in this system have names, not designations. The designations under the system "A2", etc., do not correspond to ISO paper sizes.

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. Please refer to the ISO Envelope sizes for an overview of envelopes used troughout Europe.

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