cm to mm – convert centimetres to millimetres
Convert centimetres to millimetres (cm to mm) for everyday measurements, DIY projects, school work and technical drawings. This page opens the main length converter with cm → mm pre-selected.
Open the interactive cm → mm converter:
Use main converter (cm → mm) or switch to mm → cmOn the homepage you can also convert between millimetres, centimetres, metres, kilometres, inches, feet and yards.
Quick reference: cm to mm
There are exactly 10 mm in 1 cm, so: millimetres = centimetres × 10. Some quick examples:
| Length (cm) | Length (mm) |
|---|---|
| 0.5 cm | 5 mm |
| 1 cm | 10 mm |
| 2.5 cm | 25 mm |
| 10 cm | 100 mm |
| 25 cm | 250 mm |
| 100 cm | 1,000 mm |
Why convert centimetres to millimetres?
cm to mm is handy when you:
- Need extra precision for cutting, drilling or 3D printing.
- Read technical drawings or datasheets that use millimetres only.
- Scale measurements from a ruler or tape measure into smaller units.
- Prepare school maths or design work in consistent metric units.
Other length converters on this site
All conversions here are exact metric relationships – no rounding errors from imperial conversions.
Page last updated: 11 December 2025.