HesapHanem

Paper Size Lookup Calculator

Enter a paper size name to see its dimensions.

How it is calculated

The tool looks up the name you type (case does not matter, extra spaces at the ends are ignored) in a built-in table of portrait width × height in millimetres. It knows A0 to A10, B0 to B10, C0 to C10, and the US sizes Letter, Legal, Tabloid (also Ledger, shown upright) and Executive, each also with US in front. Inches are mm / 25.4, rounded to two decimals. The ratio is height / width shown as 1 : x to three decimals. A-series sizes all have ratio 1.414 (√2), which is why halving a sheet keeps its shape. A name not in the table, such as RA2 or JIS B5, gives no result, and a space inside the name ("A 4") is not accepted.

Worked example

Look up A4. The table gives 210 × 297 mm, shown as 210.0 × 297.0 mm. In inches: 210 / 25.4 = 8.27 and 297 / 25.4 = 11.69, so 8.27 × 11.69 in. Ratio: 297 / 210 = 1.414, shown as 1 : 1.414. For comparison, US Letter is 215.9 × 279.4 mm (8.50 × 11.00 in) with ratio 1 : 1.294, so a Letter sheet is a little wider and shorter than A4.

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Common mistakes

  • Typing the size with a space or a dash ("A 4", "A-4"). The name must be written like A4 or Letter; others give no result.
  • Assuming every paper name is covered. ISO A, B and C and the main US sizes are in the table; JIS B sizes and press formats such as RA and SRA are not.
  • Swapping width and height. The dimensions are portrait, width first; rotate them for landscape.
  • Printing a Letter document on A4 (or vice versa) without scaling. The sheets differ by several millimetres in each direction, which can crop margins.
  • Reading the ratio as width : height. It is 1 : height / width, so values above 1 mean the sheet is taller than wide.

About this calculator

The ISO 216 standard defines the A series — A0 has an area of exactly 1 m², and each subsequent size (A1, A2, A3, A4 = 210×297 mm...) is half the area of the one before — along with the related B series (and a C series for envelopes, which this lookup does not include), used almost everywhere outside North America. The US paper sizes (Letter 8.5×11 in, Legal 8.5×14 in, Tabloid 11×17 in) instead follow the ANSI/ASME Y14.1 standard.

This lookup returns the exact millimeter and inch dimensions and aspect ratio for A0–A8, B0–B5, and US Letter, Legal and Tabloid. It's a reference used by graphic designers, print shops, and office workers preparing documents, templates, or print jobs for the correct regional paper standard.

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Comments (1)

  • Editorial team

    A handy check when printing across standards: scaling a Letter page to fit A4 shrinks it to about 97 percent, because A4 is narrower but taller. C sizes are made for envelopes, so a C4 envelope holds an unfolded A4 sheet and a C5 holds one folded once. Japanese B sizes differ from ISO B, and only ISO B is listed here. What are you printing or posting?

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