📄 Paper Sizes
A5 (size) to mm Converter
Convert A5 (size) to mm instantly with a reference conversion table.
A5 (size) to mm
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Common conversions
| A5 (size) | mm |
|---|
Formula:
How to convert A5 (size) to mm
1
Enter your value
Type the number of a5 (size) you want to convert into the left box. The result in mm appears instantly in the right box. You can also type into the right box to convert in the other direction.
2
Use the swap button
Click the ⇄ Swap button to reverse the conversion — mm to A5 (size). Your current value carries across so you don't have to re-enter anything.
3
About A5 (size) and mm
A5 (size) and mm are common paper measurements.
💡 Did you know?
A5 = 148 × 210 mm (half an A4 sheet). The A-series works because the aspect ratio is √2 — folding any A-size in half gives the next A-size exactly. A5 is the most popular notebook size in the UK (Leuchtturm, Moleskine, Rhodia all default to A5).
Reviewed for 2026. A5 (size) ↔ mm conversion factor verified against published reference data. Built by a UK-based qualified primary teacher and FA Level 2 coach as part of 247QuickTools' free utility-tools project.