Convert centimeters to millimeters
Converting centimeters to millimeters is a common length task, whether you are checking a recipe, a spec sheet, a travel distance or a homework problem. Since 1 cm equals 10 mm, the math is a single multiplication — and this page does it for you instantly, with the formula, a table of common values and answers to the questions people ask most.
Exact factor
How to convert centimeters to millimeters
To convert centimeters to millimeters, multiply the number of centimeters by 10. For example, 10 cm × 10 = 100 mm.
mm = cm × 10
- Write down the value in centimeters you want to convert.
- Multiply it by 10 (the exact cm→mm factor).
- The result is your value in millimeters. Check it below with the converter or the table.
Conversion table
Common values of centimeters and their equivalents in millimeters:
| cm | mm |
|---|---|
| 1 | 10 |
| 2 | 20 |
| 3 | 30 |
| 4 | 40 |
| 5 | 50 |
| 10 | 100 |
| 20 | 200 |
| 25 | 250 |
| 50 | 500 |
| 100 | 1,000 |
| 250 | 2,500 |
| 500 | 5,000 |
About these units
Centimeter (cm). A centimeter is one hundredth of a meter, roughly the width of a fingernail. It is the everyday unit for body measurements, clothing sizes and small objects in metric countries.
Millimeter (mm). A millimeter is one thousandth of a meter, the smallest length unit in everyday metric use. It is the standard precision unit in engineering drawings, machining and rainfall measurement.
Frequently asked questions
How do I convert centimeters to millimeters?
To convert centimeters to millimeters, multiply the number of centimeters by 10. For example, 10 cm × 10 = 100 mm. Or skip the math: type the value into the converter at the top of this page and the result updates instantly.
How many millimeters are in 1 centimeter?
1 cm = 10 mm. That is the fixed relationship used by this converter and by international standards.
How many centimeters are in 1 millimeter?
1 mm = 0.1 cm. If you are converting in the opposite direction, use our Millimeter to Centimeter converter for the dedicated table and FAQ.
Is the centimeters to millimeters conversion exact?
Yes. Both units are defined by international agreement, so the factor of 10 is exact. Displayed results are rounded to 6 significant digits only for readability.
What is centimeter used for?
A centimeter is one hundredth of a meter, roughly the width of a fingernail. It is the everyday unit for body measurements, clothing sizes and small objects in metric countries.