Paper Size Converter

Format

Orientation

Resolution, DPI

Result

Millimetres210 × 297
Centimetres21 × 29.7
Inches8.27 × 11.69
Pixels at that DPI2480 × 3508
Area, m²0.0624
Aspect ratio1.4143

Every format is half the one before it

Gives the dimensions of A0–A7, B4, B5, Letter and Legal in millimetres, centimetres, inches and pixels at a chosen resolution.

The A series is built on a single property: the sides are in the ratio of the square root of two, so a sheet folded in half keeps its proportions. A0 has an area of exactly one square metre, A1 half of that, A4 one sixteenth.

American formats do not follow that logic. Letter is wider and shorter than A4, so a document laid out for one loses margins or gets clipped when printed on the other.

What this calculator shows

The format in millimetres, centimetres and inches
The pixel dimensions at your chosen print resolution
Sheet area and the aspect ratio

What to keep in mind

Dimensions follow ISO 216 for the A and B series and the North American standard for Letter, Legal and Tabloid.
Pixel sizes ignore margins: on most printers the real printable area is 5 to 10 millimetres smaller on each side.

FAQs

What size is A4?

210 by 297 millimetres, or 21 by 29.7 centimetres, or 8.27 by 11.69 inches.

How many pixels is A4?

2480 by 3508 at 300 DPI, 1240 by 1754 at 150 DPI and 595 by 842 at 72 DPI.

How does Letter differ from A4?

Letter is 6 millimetres wider and 18 shorter. A document laid out for A4 gets clipped at the bottom when printed on Letter.

Why does the A series have such an odd aspect ratio?

The square root of two is the only ratio where folding a sheet in half preserves its proportions. That is what lets you scale between formats without redoing the layout.

Worked example

A4 for print

Input: A4, portrait, 300 DPI

Output: 210 × 297 mm, which is 2480 × 3508 pixels

Note: The aspect ratio is 1.414, the square root of two. Which is why two A4 pages side by side make an exact A3 with nothing trimmed, and why Letter and Legal do not behave that way.

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Paper Size Converter

Result

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DPI and Print Size Calculator

Aspect Ratio Calculator

Length Converter

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