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Paper Size Chart – A4, Letter, A3 and More in mm, Inches and Pixels

Look up the exact size of any common paper format — ISO A0 to A8, B4 and B5, C-series and DL envelopes, US Letter, Legal and Tabloid, photo sizes and business cards — in millimetres, centimetres, inches and pixels at the resolution you need.

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How to use the paper size chart

  1. Pick a paper size. People in the US, Canada and Mexico start on Letter; everyone else on A4.
  2. Pick the DPI (dots per inch) you need for pixel sizes.

You’ll see the size in millimetres, centimetres and inches, the pixel size at your DPI, the aspect ratio, and a table of every size.

How the sizes are worked out

ISO sizes start from A0, which has an area of one square metre. Each next size is half the previous one:

A(n+1) = A(n) cut in half across the long side

To get pixels from a physical size:

pixels = (millimetres ÷ 25.4) × DPI

Worked example

A4 at 300 DPI: 210 ÷ 25.4 × 300 = 2,480 pixels wide and 297 ÷ 25.4 × 300 = 3,508 pixels tall.

Most-used sizes

Sizemminches
A3297 × 42011.69 × 16.54
A4210 × 2978.27 × 11.69
A5148 × 2105.83 × 8.27
A6105 × 1484.13 × 5.83
Letter215.9 × 279.48.5 × 11
Legal215.9 × 355.68.5 × 14
Tabloid279.4 × 431.811 × 17

Which DPI should I use?

  • 72 or 96 DPI: screens, web images and email.
  • 150 DPI: drafts and documents printed at home.
  • 300 DPI: standard for professional printing, flyers and photos.
  • 600 DPI: fine line art and high-quality scans.

A higher DPI means more pixels and bigger files. For an image you want to print at A4 without blurring, make it at least 2,480 × 3,508 pixels.

Where each size is used

  • A4 is the standard office paper across Europe, Africa, Asia, Australia and Latin America.
  • Letter is the US and Canadian standard; Legal is used for some contracts and forms.
  • A5 is popular for notebooks, flyers and booklets; A6 for postcards.
  • A3 and Tabloid are used for posters, spreadsheets and drawings.
  • 4 × 6 in is the standard photo print size, also called 10 × 15 cm.

B and C sizes

ISO B sizes sit between the A sizes — B5 is between A5 and A4 — and are used for books, passports and some posters. C sizes are for envelopes: each C size fits the matching A size flat, so a C4 envelope holds an unfolded A4 sheet. In Japan, JIS B sizes are slightly larger than ISO B sizes.

Printing tips

  • When printing a Letter document on A4 (or the reverse), choose “fit to page” to avoid cutting off margins.
  • Leave at least 3 mm bleed on artwork that runs to the edge, if a print shop asks for it.
  • Export PDFs at the paper size you intend to print, not just “fit”.

To resize an image to these dimensions, use the image resizer; to turn images into a PDF on A4 or Letter, try JPG to PDF. Convert other measurements with the cm to inches converter.

Frequently asked questions

What size is A4?

210 × 297 mm, or 8.27 × 11.69 inches. At 300 DPI that is 2,480 × 3,508 pixels; at 96 DPI it is 794 × 1,123 pixels.

What size is US Letter?

8.5 × 11 inches, or 215.9 × 279.4 mm. It is slightly wider and shorter than A4 and is the standard in the US, Canada and Mexico.

How many pixels is A4 at 300 DPI?

2,480 × 3,508 pixels. Print shops usually ask for 300 DPI for sharp results.

What size is A3?

297 × 420 mm (11.69 × 16.54 in) — exactly two A4 sheets side by side.

Why do A sizes have the same shape?

ISO paper has a width-to-height ratio of 1 : √2 (about 1 : 1.414). Cutting a sheet in half across its long side gives two sheets of the next size with the same shape, so you can scale documents without distortion.

What is a DL envelope?

110 × 220 mm — it fits an A4 sheet folded into thirds. C5 fits A4 folded once, and C4 fits A4 flat.

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