About the cm to mm calculation
One centimeter is exactly 10 millimeters, so converting between them is a single multiplication. Enter any value above and the result updates as you type. How height and clothing sizes are quoted almost everywhere outside the US. The standard fine unit on engineering drawings and rainfall figures.
Formula
mm = cm × 10
1 cm = 10 mm
1 mm = 0.1 cmWorked example
To convert 180 cm, multiply by 10: 180 × 10 = 1,800 mm.
Frequently asked questions
How many millimeters are in a centimeter?
There are 10 millimeters in one centimeter. To convert any amount, multiply the number of centimeters by 10.
How do I convert millimeters back to centimeters?
Divide instead of multiplying, or equivalently multiply by 0.1. One millimeter is 0.1 centimeters.
Is this conversion exact?
Yes. Since the international agreement of 1959, the relationship between centimeters and millimeters is defined exactly rather than measured, so the only rounding here is in how many decimal places we show.
Where is each of these units used?
Centimeters: how height and clothing sizes are quoted almost everywhere outside the US. Millimeters: the standard fine unit on engineering drawings and rainfall figures.
Sources
- NIST Special Publication 811 — Guide for the Use of the International System of Units