CM to MM Converter
Convert centimeters (cm) to millimeters (mm) instantly. Type a value — the result updates as you type, and the swap button converts the other way.
cm to mm formula
mm = cm × 10
1 centimeter = 10 millimeters · 1 millimeter = 0.1 centimeters
To convert centimeters to millimeters, multiply the value by 10. For example, 2.5 cm:
mm = 2.5 × 10mm = 25
So 2.5 cm = 25 mm.
Mental math shortcut
This conversion is exact, so there is no need to estimate: just multiply by 10.
cm to mm conversion table
mm back to cm
The same values converted the other way, rounded for everyday use:
| Millimeters | Centimeters |
|---|---|
| 1 mm | 0.1 cm |
| 5 mm | 0.5 cm |
| 10 mm | 1 cm |
| 15 mm | 1.5 cm |
| 20 mm | 2 cm |
| 25 mm | 2.5 cm |
| 50 mm | 5 cm |
| 100 mm | 10 cm |
About the units
Centimeters (cm)
A centimeter is one hundredth of a meter. It is the everyday metric unit for body height, clothing and short lengths.
Millimeters (mm)
A millimeter is one thousandth of a meter (0.1 cm). It is used for small, precise measurements like rainfall, screws and paper thickness.
Frequently asked questions
How many millimeters are in a centimeter?
One centimeter equals 10 millimeters.
What is 2.5 cm in mm?
2.5 cm = 25 mm.
How do I convert mm back to cm?
Divide the millimeters by 10. Or use the MM to CM converter.