Convert Centimetre to Millimetre
Turn Centimetres into Millimetres in an instant. Type a value below to get an accurate cm → mm result, with the formula and a quick-reference table.
1 cm = 10 mm
Quick answer: 1 Centimetre = 10 Millimetre
Centimetre to Millimetre conversion table
| Centimetre (cm) | Millimetre (mm) |
|---|---|
| 1 cm | 10 mm |
| 2 cm | 20 mm |
| 5 cm | 50 mm |
| 10 cm | 100 mm |
| 20 cm | 200 mm |
| 50 cm | 500 mm |
| 100 cm | 1,000 mm |
| 500 cm | 5,000 mm |
| 1,000 cm | 10,000 mm |
How to convert Centimetre to Millimetre
To convert Centimetres to Millimetres, multiply the value by 10.
- Take your measurement in Centimetres.
- Multiply it by 10 — the number of Millimetres in one Centimetre.
- The result is the same amount, expressed in Millimetres.
To go the other way, multiply Millimetres by 0.1 — or simply divide by 10.
For example, a school ruler is about 30 cm, which is 300 mm.
About Centimetre and Millimetre
A centimetre is one-hundredth of a metre, or 10 millimetres. It is the unit most people reach for to measure height, paper sizes and small objects in metric countries.
A millimetre is one-thousandth of a metre (1/1000 m) — the smallest line printed on a standard ruler. It is the everyday unit for fine measurements such as engineering tolerances, screw threads, paper thickness and rainfall.
Both the Centimetre and the Millimetre are metric units, so converting between them is just a change of scale: one Centimetre equals 10 Millimetres, and the Centimetre is the larger unit.
Other length conversions
Frequently asked questions
How many Millimetres are in a Centimetre?
1 Centimetre equals 10 Millimetre (cm → mm). To convert any amount, multiply the number of Centimetres by 10.
How do I convert Centimetre to Millimetre?
Enter the number of Centimetres in the converter above and read the result in Millimetres. It applies the exact cm → mm factor instantly, with full precision.
Is the Centimetre to Millimetre converter free?
Yes — it is completely free and unlimited, needs no sign-up, and runs right in your browser, so it is instant and private.
Is the conversion accurate?
Yes. It uses the internationally defined length factors and full floating-point precision, then rounds the display to a clean, readable number.