A4 size in cm, inches and pixels
A4 size in cm is 21 × 29.7, which is 210 × 297 mm and 8.27 × 11.69 inches.
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For an A4 frame, look for an opening of 210 × 297 mm. A4 is taller and narrower than US Letter (8.5 × 11 inches). We print A4 on paper without a frame; our framed prints start at A3.
A4 is 210 × 297 mm, which is 21 × 29.7 cm and 8.27 × 11.69 inches.
A4 size in cm, plus inches and pixels at each dpi
| Millimeters | 210 × 297 mm |
|---|---|
| Centimeters | 21 × 29.7 cm |
| Inches | 8.27 × 11.69 in |
| Pixels at 72 dpi | 595 × 842 px |
| Pixels at 150 dpi | 1240 × 1754 px |
| Pixels at 300 dpi | 2480 × 3508 px |
A4 is A0 halved four times, and the unit every other size gets described against. How the A series is defined is on the hub.
How the A series reaches A4
Four halvings from the top. A0 measures 841 × 1189 mm; the cuts give A1 at 594 × 841, A2 at 420 × 594, A3 at 297 × 420 and then A4 at 210 × 297. The inherited side never changes, but the halved side is rounded down where it’s odd - 1189 to 594, 841 to 420, 297 to 148 - which is why some of these sizes double exactly and some don’t.
That behaviour belongs to 1:√2 and to no other ratio, which is why the series uses it. A4 covers 62,370 mm² and is exactly half an A3: two A4 sheets make 124,740, which is an A3 to the millimetre. Going the other way it isn’t exactly twice A5: two A5s fall 210 mm² short of it, and the hub says why. The exact half is the reason the office photocopier enlarges A4 to A3 on one button with nothing falling off the edge.
Will your file carry A4?
Pixels divided by dpi gives inches, so a size's pixel requirement is just its width in inches multiplied back up. At 300 dpi, A4 needs 2480 × 3508 pixels, about 8.7 megapixels: a bar almost any phone from the last decade clears. At 150 dpi it is 1240 × 1754.
Check the product size
If a size is on a product page, we print it. Your file gets checked against those sizes before you order, and the page drops any size it is too small for.
Size references
The A4 numbers follow ISO 216, the standard for A and B paper. Inch conversions use the inch as NIST defines it, exactly 25.4 mm. See the poster sizes we print before ordering.
Print your artwork at A4
A4 is the smallest poster we print, on 250 gsm uncoated off-white archival paper, with free UK delivery. Print your artwork at A4.
Pixel and print-size converter
What each size needs, computed from ISO 216
| Size | Millimetres | 72 dpi | 150 dpi | 300 dpi |
|---|---|---|---|---|
| A1 | 594 × 841 mm | 1684 × 2384 px | 3508 × 4967 px | 7016 × 9933 px |
| A2 | 420 × 594 mm | 1191 × 1684 px | 2480 × 3508 px | 4961 × 7016 px |
| A3 | 297 × 420 mm | 842 × 1191 px | 1754 × 2480 px | 3508 × 4961 px |
| A4 | 210 × 297 mm | 595 × 842 px | 1240 × 1754 px | 2480 × 3508 px |
| A5 | 148 × 210 mm | 420 × 595 px | 874 × 1240 px | 1748 × 2480 px |
Divide pixels by dpi and you have the size in inches. Three hundred dpi is a convention for things held close, not a rule; a print read from across a room is untroubled at 150. Every size above is worked from the ISO 216 definition: A0 is 841 × 1189 mm and each size halves the longer side, rounded down to whole millimetres.
Print your file at this size
Upload the file you just checked. The buy box grades it against every size, shows you the crop, and only lets you choose sizes it will print sharply.
Questions and answers
What size is A4 in cm?
A4 is 21 × 29.7 cm, or 210 × 297 mm.
What is A4 in inches?
8.27 × 11.69 inches.
How many pixels is A4 at 300 dpi?
2480 × 3508 pixels. At 150 dpi it is 1240 × 1754, and at 72 dpi 595 × 842.
Is A4 bigger than A5?
Yes, by a little over double: 62,370 mm² against 31,080. Half of 297 mm is 148.5 and ISO 216 rounds A5 down to 148, so two A5 sheets come 210 mm² short of an A4.