Dealing with envelopes can get complicated. There are a few VERY common envelopes such as a #10 (the standard business letterhead envelope) and a #9 (the standard reply envelope that comes with all of your bills) and then there are tons of other “standard” sizes such as A2, A7, 4-Bar, #6 3/4 and so on.
This page focuses on the “A” sizes of envelopes in particular. A-envelopes are typically used for more formal communications such as invitations. They are made from thicker paper stock and usually come in a wider variety of colors and finished than some of the other envelope sizes. Most A-envelopes also have side seams (the back of the envelope is put together with two vertical glue seams as opposed to three triangular flaps) which give a more finished look to the envelope.
A-Envelope Sizes (inches):
- A1 Envelopes – 3 5/8 x 5 1/8
- A2 Envelopes – 4 3/8 x 5 3/4
- A6 Envelopes – 4 3/4 x 6 1/2
- A7 Envelopes – 5 1/4 x 7 1/4
- A8 Envelopes – 5 1/2 x 8 1/8
- A9 Envelopes – 5 3/4 x 8 3/4
- A10 Envelopes – 6 x 9 1/2
A-Envelope Insert Sizes (inches):
- A1 Envelopes fits 3 1/2 x 4 7/8 inserts
- A2 Envelopes fits 4 1/4 x 5 1/2 inserts
- A6 Envelopes fits 4 1/2 x 6 1/4 inserts
- A7 Envelopes fits 5 1/8 x 7 inserts
- A8 Envelopes fits 5 3/8 x 7 7/8 inserts
- A9 Envelopes fits 5 1/2 x 8 1/2 inserts
- A10 Envelopes fits 5 3/4 x 9 1/4 inserts