Centimeter is 0.01 meter units.
Centimeters to Millimeters Converter — cm to mm
Convert Centimeter (cm) to Millimeter (mm) using the exact conversion factor (1 centimeter = 10 millimeter). See the formula, worked examples, conversion table, unit comparison, history, and common uses.
Centimeters to Millimeters converter
Converter
Length Converter
Convert SI, imperial, US customary, astronomical, scientific, and historical length units.
Context values
Some unit families need one extra value for a physically accurate result.
Millimeter is 0.001 meter units.
Result = input x 0.01 / 0.001.
Length uses the meter as the base unit.
Reserved above the conversion cards and below the converter.
About Converting Centimeters to Millimeters
Centimeter and Millimeter both measure length. Centimeter is typically associated with standard small-length unit worldwide except the US, while Millimeter is typically associated with standard small/precision length unit worldwide, including in US engineering and manufacturing.
Formula
millimeters = centimeters × 10
This factor comes from each unit's defined relationship to the category's base unit: 1 centimeter equals 0.01 base units, and 1 millimeter equals 0.001 base units, so dividing one by the other gives the direct centimeter-to-millimeter factor of 10.
Simple example
1 cm × 10 = 10 mm
1 centimeter = 10 millimeters.
Real-world example
10 cm × 10 = 100 mm
10 centimeters = 100 millimeters.
Conversion table
| Centimeter (cm) | Millimeter (mm) |
|---|---|
| 1 cm | 10 mm |
| 5 cm | 50 mm |
| 10 cm | 100 mm |
| 21.0975 cm | 210.975 mm |
| 42.195 cm | 421.95 mm |
| 100 cm | 1,000 mm |
Reverse conversion: Millimeter to Centimeter
10 mm × 0.1 = 1 cm
10 millimeters = 1 centimeter.
centimeters = millimeters × 0.1
For a page dedicated to this direction, see Millimeter to Centimeter.
Centimeter vs. Millimeter
| Aspect | Centimeter | Millimeter |
|---|---|---|
| Family | SI derived (metric prefix) unit | SI derived (metric prefix) unit |
| Typical use | Everyday small-object and body measurement (height, clothing sizes) outside the US | Engineering drawings and manufacturing tolerances worldwide (including in the US) |
| Where it's used | Standard small-length unit worldwide except the US | Standard small/precision length unit worldwide, including in US engineering and manufacturing |
Understanding the Centimeter
Centimeter (cm) measures distance. A centimeter is one-hundredth of a meter. It is classified as a SI derived (metric prefix) unit.
Where it's used: Standard small-length unit worldwide except the US
Uses of the Centimeter today
- Everyday small-object and body measurement (height, clothing sizes) outside the US
- Construction and manufacturing tolerances internationally
History of the Centimeter
The centimeter follows directly from the meter via the 'centi-' SI prefix (10⁻²), introduced with the metric system in the 1790s.
Historical origin. Centimeter was not the invention of a single named person; it developed through the process described above.
Understanding the Millimeter
Millimeter (mm) measures distance. A millimeter is one-thousandth of a meter. It is classified as a SI derived (metric prefix) unit.
Where it's used: Standard small/precision length unit worldwide, including in US engineering and manufacturing
Uses of the Millimeter today
- Engineering drawings and manufacturing tolerances worldwide (including in the US)
- Rainfall measurement in most countries
- Small-scale everyday measurement (screen sizes, hardware)
History of the Millimeter
The millimeter follows from the meter via the 'milli-' SI prefix (10⁻³). It is notable as one of the few metric units in routine US technical/engineering use, since precision manufacturing and electronics are often specified in millimeters even in the US.
Historical origin. Millimeter was not the invention of a single named person; it developed through the process described above.
Centimeter — sources
- BIPM SI Brochure — SI prefixes — Defines 'centi-' as the prefix for 10⁻².
Millimeter — sources
- BIPM SI Brochure — SI prefixes — Defines 'milli-' as the prefix for 10⁻³.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many millimeters are in 1 centimeter?
1 centimeter equals 10 millimeters, using the exact defined conversion factor rather than an estimate.
How do I convert centimeter to millimeter?
Multiply the centimeter value by 10. The converter above does this instantly to whatever precision you set.
How do I convert millimeter back to centimeter?
Use the reverse factor: 1 millimeter equals 0.1 centimeters. You can also use the swap control in the converter above to flip the direction instantly.
What is a centimeter?
Centimeter (cm) measures distance. A centimeter is one-hundredth of a meter. It is classified as a SI derived (metric prefix) unit.
What is a millimeter?
Millimeter (mm) measures distance. A millimeter is one-thousandth of a meter. It is classified as a SI derived (metric prefix) unit.
Is the centimeter to millimeter conversion exact?
Yes. Both centimeter and millimeter are defined by fixed standards rather than physical artifacts, so the factor of 10 used above is exact to as many digits as you choose to display.
Where is the centimeter still used today?
Standard small-length unit worldwide except the US