Paper Size Converter
A4, Letter, B & C series.
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About Paper Size Converter
Look up any paper size in millimetres, centimetres and inches — the full ISO A, B and C series plus US Letter, Legal and Tabloid — and get the print-scaling percentage to fit one size onto another.
A generic converter gives you the dimensions but not the number you actually need: what percentage to set in the print dialog so A4 fits on US Letter (about 94%) without being cut off. It is completely free with no sign-up, and it runs entirely in your browser.
Frequently asked questions
- What is A4 in inches?
- A4 is 8.27 × 11.69 inches, or 210 × 297 mm. The tool shows every size in mm, cm and inches.
- How do I print an A4 document on US Letter paper?
- Set your printer's scale to about 94% (or choose 'Fit to page'). A4 is taller than Letter, so shrinking it slightly stops the bottom being cut off. The scaling calculator gives the exact figure for any pair of sizes.
- What's the difference between A4 and US Letter?
- A4 (210 × 297 mm) is a little narrower and noticeably taller than US Letter (216 × 279 mm), so they're not interchangeable without scaling.
- What are the B and C paper series for?
- The B series sits between A sizes (used for posters and books), and the C series is sized for envelopes — a C4 envelope holds an unfolded A4 sheet, a C5 holds a folded one.
- How do the ISO paper sizes work?
- Each size is the previous one halved, keeping the same proportions, with dimensions rounded down to whole millimetres — so A5 is half of A4, A6 is half of A5, and so on.