📄 Paper Size Reference

A-Series (ISO 216)

Size	mm	inch
A0	841 × 1,189 mm	33.11 × 46.81 in
A1	594 × 841 mm	23.39 × 33.11 in
A2	420 × 594 mm	16.54 × 23.39 in
A3	297 × 420 mm	11.69 × 16.54 in
A4	210 × 297 mm	8.27 × 11.69 in
A5	148 × 210 mm	5.83 × 8.27 in
A6	105 × 148 mm	4.13 × 5.83 in
A7	74 × 105 mm	2.91 × 4.13 in
A8	52 × 74 mm	2.05 × 2.91 in
A9	37 × 52 mm	1.46 × 2.05 in
A10	26 × 37 mm	1.02 × 1.46 in

B-Series (JIS P 0138, Japan)

Size	mm	inch
B0	1,030 × 1,456 mm	40.55 × 57.32 in
B1	728 × 1,030 mm	28.66 × 40.55 in
B2	515 × 728 mm	20.28 × 28.66 in
B3	364 × 515 mm	14.33 × 20.28 in
B4	257 × 364 mm	10.12 × 14.33 in
B5	182 × 257 mm	7.17 × 10.12 in
B6	128 × 182 mm	5.04 × 7.17 in
B7	91 × 128 mm	3.58 × 5.04 in
B8	64 × 91 mm	2.52 × 3.58 in
B9	45 × 64 mm	1.77 × 2.52 in
B10	32 × 45 mm	1.26 × 1.77 in

B-Series (ISO 216)

Size	mm	inch
B0	1,000 × 1,414 mm	39.37 × 55.67 in
B1	707 × 1,000 mm	27.83 × 39.37 in
B2	500 × 707 mm	19.69 × 27.83 in
B3	353 × 500 mm	13.90 × 19.69 in
B4	250 × 353 mm	9.84 × 13.90 in
B5	176 × 250 mm	6.93 × 9.84 in
B6	125 × 176 mm	4.92 × 6.93 in
B7	88 × 125 mm	3.46 × 4.92 in
B8	62 × 88 mm	2.44 × 3.46 in
B9	44 × 62 mm	1.73 × 2.44 in
B10	31 × 44 mm	1.22 × 1.73 in

US Sizes

Size	mm	inch
Letter	215.9 × 279.4 mm	8.50 × 11.00 in
Legal	215.9 × 355.6 mm	8.50 × 14.00 in
Tabloid	279.4 × 431.8 mm	11.00 × 17.00 in

A quick reference chart for A-series (A0–A10), Japanese B-series (JIS, B0–B10), international B-series (ISO, B0–B10) and US paper sizes (Letter, Legal, Tabloid), shown in millimeters and inches. The "B5" and "B4" of Japanese copy paper and notebooks are JIS sizes. Useful for print design or checking paper sizes when working with people overseas.

How to use

Look at the section for the standard you want (A-series, JIS B, ISO B or US sizes).
Each size is listed with both its mm and inch dimensions.

How the calculation works

Every A- and B-series sheet has sides in the ratio 1 : √2 (about 1 : 1.414). A sheet with this ratio keeps the same shape when folded in half across its long side, so two A4 sheets side by side make A3, half of A3 is A4, and each step in the number doubles or halves the area. A0 is defined to have an area of one square metre (841 × 1189 mm), and A1, A2 and so on are successive halves. ISO B sizes sit between neighbouring A sizes (B0 is 1000 × 1414 mm). Japan's JIS B sizes are defined to have 1.5 times the area of the matching A size (B0 is 1030 × 1456 mm, about 1.5 m²), so their sides are about 3% longer than ISO B sizes with the same number. Inch figures are millimetres divided by 25.4, shown to two decimal places. The US sizes Letter, Legal and Tabloid were originally defined in inches (Letter is 8.5 × 11 in).

Worked example

A4 and A3 A4: 210 × 297 mm A3: 297 × 420 mm (A4's long side becomes A3's short side; the area doubles) JIS B4 and ISO B4 JIS B4: 257 × 364 mm (about 93,500 mm²) ISO B4: 250 × 353 mm (about 88,250 mm²) A4 and US Letter A4: 210 × 297 mm (8.27 × 11.69 in) Letter: 215.9 × 279.4 mm (8.5 × 11 in) Letter is about 6 mm wider and 18 mm shorter.

Things to be aware of

In Japan, "B5" or "B4" almost always means the JIS size. State JIS or ISO explicitly when ordering from printers abroad.
Printing an A4 document on Letter paper can cut off the top or bottom or shift the margins. Check the "fit to page" setting when printing.
These are trimmed sizes. Print-ready files usually add about 3 mm of bleed on each side.

FAQ

Is this different from Japan's JIS B-series?

Yes. The "B5" and "B4" used for copy paper, notebooks and books in Japan are JIS sizes, slightly larger than ISO: JIS B5 is 182 × 257 mm while ISO B5 is 176 × 250 mm. This page lists both tables.

How big is A4?

210mm × 297mm (about 8.27 × 11.69 inches) — the most common copy paper size in Japan and Europe.

What's the difference between US Letter and A4?

US Letter (215.9mm × 279.4mm) is slightly wider and shorter than A4. It's mainly used in North America.