Calculate millimeters from centimeters instantly by multiplying centimeters by 10, with reverse mm to cm conversion and a quick reference chart.
Centimeters to Millimeters Formula
mm = cm * 10
To go the other way, divide instead of multiply:
cm = mm / 10
- mm is the length in millimeters.
- cm is the length in centimeters.
- 10 is the fixed number of millimeters in one centimeter.
A centimeter is ten times longer than a millimeter, so every centimeter you enter becomes 10 millimeters in the result. The converter multiplies your centimeter value by 10 to give millimeters, and when you switch the direction it divides the millimeter value by 10 to give centimeters. The decimal places setting only changes how the answer is displayed; the underlying factor of 10 is exact and never rounds. The optional other length units view rescales the same length into meters, inches, and feet using their standard millimeter sizes.
Centimeter to Millimeter Conversion Chart
Use this table to check common values or to estimate a result without entering anything.
| Centimeters (cm) | Millimeters (mm) |
|---|---|
| 0.5 cm | 5 mm |
| 1 cm | 10 mm |
| 2 cm | 20 mm |
| 5 cm | 50 mm |
| 10 cm | 100 mm |
| 25 cm | 250 mm |
| 100 cm | 1,000 mm |
Example Problems
Example 1. You measure a phone screen at 14.5 cm and need the value in millimeters. Multiply by 10: 14.5 * 10 = 145 mm.
Example 2. A drill bit is labeled 8 mm and you want centimeters. Divide by 10: 8 / 10 = 0.8 cm.
FAQ
How many millimeters are in a centimeter?
There are exactly 10 millimeters in 1 centimeter. Both units come from the metric system, where each step changes the size by a factor of 10, so the conversion is always a clean multiply or divide by 10.
How do you convert centimeters to millimeters without a calculator?
Move the decimal point one place to the right, which is the same as multiplying by 10. For example, 3.7 cm becomes 37 mm, and 0.25 cm becomes 2.5 mm.
Which is larger, a centimeter or a millimeter?
A centimeter is larger. One centimeter spans the same distance as 10 millimeters, so it takes 10 of the smaller millimeter marks to cover a single centimeter on a ruler.
