A1 Envelope (US) paper size
92.075 × 130.175 mm
3.63 × 5.13 inches · 9.21 × 13.02 cm · aspect ratio 1:1.41
A1 Envelope (US) size is 92.075 × 130.175 mm. Those are the A1 Envelope (US) dimensions a printer works to; the same sheet in centimetres, inches, points and pixels is below.
What A1 Envelope (US) is for
A1 Envelope (US) is 3⅝ × 5⅛ inches, or 92.075 × 130.175 mm. The smallest of the US announcement envelopes, sold as an A1 or a 4 Bar depending on the supplier, and used for reply cards and short notes. It has nothing to do with ISO A1, which is a sheet the size of a small table.
A1 Envelope (US) dimensions in every unit
| Unit | Width | Height |
|---|---|---|
| Millimetres | 92.075 mm | 130.175 mm |
| Centimetres | 9.21 cm | 13.02 cm |
| Inches | 3.63 in | 5.13 in |
| Points (PostScript) | 261 pt | 369 pt |
A1 Envelope (US) in pixels
Pixel dimensions depend entirely on the resolution you are working at — there is no single "pixel size" for a sheet of paper. Every resolution, with file sizes and canvas setup →
| Resolution | Pixels | Use |
|---|---|---|
| 72 DPI | 261 × 369 | Screen preview only — far too coarse to print |
| 150 DPI | 544 × 769 | Draft printing, internal documents |
| 300 DPI | 1088 × 1538 | The standard for commercial print |
| 600 DPI | 2175 × 3075 | Fine detail, line art, archival scanning |
Setting up a print document? Use 300 DPI and add 3 mm of bleed on every edge unless your printer specifies otherwise.
How A1 Envelope (US) relates to the rest of the series
At 92.075 × 130.175 mm (3.63 × 5.13 inches) the aspect ratio is 1:1.414. US envelopes are not a halving series: each size is cut to hold a particular sheet or card, so the numbers step irregularly and nothing scales cleanly to anything else.
Of the standard sheets on this site, the largest that goes in flat is Index Card 3×5 at 76.2 × 127 mm, with a few millimetres to spare on each edge.
No standard sheet folds down small enough to go in, which puts it in the card and reply-slip range rather than the business range.
About A1 Envelope (US)
3.625 × 5.125 inches. The smallest US announcement envelope, also sold as a 4 Bar. Unrelated to ISO A1.
Other US envelope sizes sizes
| Size | Millimetres | Inches |
|---|---|---|
| Envelope No. 10 | 104.775 × 241.3 mm | 4.13 × 9.5 in |
| A7 Envelope (US) | 133.35 × 184.15 mm | 5.25 × 7.25 in |
| A2 Envelope (US) | 111.125 × 146.05 mm | 4.38 × 5.75 in |
| A6 Envelope (US) | 120.65 × 165.1 mm | 4.75 × 6.5 in |
| A8 Envelope (US) | 139.7 × 206.375 mm | 5.5 × 8.13 in |
| A9 Envelope (US) | 146.05 × 222.25 mm | 5.75 × 8.75 in |
| A10 Envelope (US) | 152.4 × 241.3 mm | 6 × 9.5 in |
| Envelope No. 6 3/4 | 92.075 × 165.1 mm | 3.63 × 6.5 in |
| Envelope No. 9 | 98.425 × 225.425 mm | 3.88 × 8.88 in |
| Envelope No. 11 | 114.3 × 263.525 mm | 4.5 × 10.38 in |
| Envelope No. 12 | 120.65 × 279.4 mm | 4.75 × 11 in |
| Envelope No. 14 | 127 × 292.1 mm | 5 × 11.5 in |
Frequently asked questions
What size is A1 Envelope (US) in mm?
92.075 × 130.175 mm.
What size is A1 Envelope (US) in inches?
3.63 × 5.13 inches.
What size is A1 Envelope (US) in pixels?
There is no single answer — it depends on resolution. At the print standard of 300 DPI it is 1088 × 1538 pixels; at 72 DPI it is only 261 × 369.