US envelope sizes (#10, A7 and more)
Gives metric dimensions for the common business, card and catalog envelopes used in North America.
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How to use it
- Enter envelope.
- The result appears straight away and updates as you edit.
- Copy the result, or copy a link that keeps the same values to share it.
How it is calculated
Nominal size in inches × 25.4 = millimetres, then ÷ 10 = centimetres.
Example
Inputs: Envelope = #10 (4 1/8 × 9 1/2 in). Result: Size in inches: 4.125 × 9.5 in; Width: 104.77 mm; Length: 241.3 mm.
Limits and caveats
- Sizes are nominal outer dimensions and can differ by a fraction of an inch between makers.
Questions about this tool
What is a #10 envelope in cm?
It is 4 1/8 × 9 1/2 in, or 10.48 × 24.13 cm, and holds a Letter sheet folded in thirds.
What is an A7 envelope?
A card envelope of 5 1/4 × 7 1/4 in, usually used for 5 × 7 in invitations.
Is a US A7 envelope related to ISO A7 paper?
No. The A here names the American card envelope line and has nothing to do with ISO A7.