How many millimetres are in a centimetre?

There are exactly 10 millimetres in a centimetre. That means 1 cm = 10 mm.

What is the formula to convert centimetres to millimetres?

To convert centimetres to millimetres, multiply by 10. The formula is: millimetres = centimetres × 10.

Where is cm to mm conversion used?

Centimetres to millimetres is used in school maths, technical drawings, 3D printing, woodworking, sewing, and anywhere you need smaller metric units for extra precision.

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 → cm

On 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.