Paper size reference
Look up A, B and C series, US Letter, Legal and ANSI paper sizes in millimetres, inches, points and pixels.
A clear answer. Here’s how.
ISO 216 sizes keep the ratio 1 : √2, so folding a sheet in half across its long side gives the next size down. A0 has an area of 1 m² and its dimensions are 841 × 1189 mm; each following size halves the area, with the sides rounded down to whole millimetres. The B series sits geometrically between the A sizes (B0 is 1 000 mm wide), and the C series between A and B for envelopes. North American sizes are defined in inches (Letter 8.5 × 11, Legal 8.5 × 14, Tabloid 11 × 17, ANSI C, D and E from 17 × 22 up), and one inch is exactly 25.4 mm. Points are 1/72 inch, the unit of PDF and PostScript. Pixels are inches × dpi, rounded.
How this is checked
4 reference checks passed These 4 cases were run when this page was built, on 20 October 2026, and all reproduce within the stated tolerance. The same cases are part of the automated tests that run on every change to Toolmoz. Engine version 1.
See the checks and where each expected answer comes from
Case 1
- Inputs
- Show A4Pixel resolution 300
- Expected, and what Toolmoz gave
- Width (mm) expected 210, Toolmoz 210Height (mm) expected 297, Toolmoz 297Width (px) expected 2480, Toolmoz 2480Height (px) expected 3508, Toolmoz 3508Width (in) expected 8.268, Toolmoz 8.267716535433072
- Where the expected answer comes from
- ISO 216 A4 is 210 × 297 mm, which is 8.268 × 11.693 in and 2480 × 3508 pixels at 300 dpi (210 ÷ 25.4 × 300 = 2480.3)
- Allowed difference
- ±0.001 absolute
Case 2
- Inputs
- Show US Letter (ANSI A)Pixel resolution 72
- Expected, and what Toolmoz gave
- Width (mm) expected 215.9, Toolmoz 215.9Height (mm) expected 279.4, Toolmoz 279.4Width (px) expected 612, Toolmoz 612Height (px) expected 792, Toolmoz 792
- Where the expected answer comes from
- Letter is 8.5 × 11 in, so 612 × 792 PostScript points and 215.9 × 279.4 mm (1 in = 25.4 mm)
- Allowed difference
- ±1e-9 absolute
Case 3
- Inputs
- Show A0Pixel resolution 72
- Expected, and what Toolmoz gave
- Width (mm) expected 841, Toolmoz 841Height (mm) expected 1189, Toolmoz 1189Width (px) expected 2384, Toolmoz 2384Height (px) expected 3370, Toolmoz 3370
- Where the expected answer comes from
- ISO 216 A0 is 841 × 1189 mm (1 m²), which is 2384 × 3370 points
- Allowed difference
- ±1e-9 absolute
Case 4
- Inputs
- Show ISO APixel resolution 96
- Expected, and what Toolmoz gave
- Sizes listed expected 11, Toolmoz 11First size expected A0, Toolmoz A0
- Where the expected answer comes from
- The A series runs from A0 to A10, eleven sizes
- Allowed difference
- exact
What this shows: the engine reproduces independently worked values for these cases. It does not prove every possible input is right. To test an answer you were given, see how to check a number; to see what is and is not checked across Toolmoz, see the accuracy ledger.
See a worked example
Worked example
A fixed demonstration, separate from the values you enter above.
- Show
- A4 (210 × 297 mm)
- Pixel resolution
- 300 dpi (print)
Example result
| Size | Width (mm) | Height (mm) | Width (in) | Height (in) | Width (pt) | Height (pt) | Width (px at 300 dpi) | Height (px at 300 dpi) |
|---|---|---|---|---|---|---|---|---|
| A4 | 210 | 297 | 8.268 | 11.693 | 595.3 | 841.9 | 2,480 | 3,508 |
ISO 216 sizes keep a 1 : √2 ratio and halve the area from one size to the next, with dimensions rounded to whole millimetres; A0 has an area of 1 m². North American sizes are defined in inches (1 in = 25.4 mm). Points are 1/72 inch (PDF and PostScript units). Pixels are inches × the chosen dpi, rounded to whole pixels.