Millimeter is 0.001 meter units.
Millimeters to Centimeters Converter — mm to cm
Convert Millimeter (mm) to Centimeter (cm) using the exact conversion factor (1 millimeter = 0.1 centimeter). See the formula, worked examples, conversion table, unit comparison, history, and common uses.
Millimeters to Centimeters 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.
Centimeter is 0.01 meter units.
Result = input x 0.001 / 0.01.
Length uses the meter as the base unit.
Reserved above the conversion cards and below the converter.
About Converting Millimeters to Centimeters
Millimeter and Centimeter both measure length. Millimeter is typically associated with standard small/precision length unit worldwide, including in US engineering and manufacturing, while Centimeter is typically associated with standard small-length unit worldwide except the US.
Formula
centimeters = millimeters × 0.1
This factor comes from each unit's defined relationship to the category's base unit: 1 millimeter equals 0.001 base units, and 1 centimeter equals 0.01 base units, so dividing one by the other gives the direct millimeter-to-centimeter factor of 0.1.
Simple example
1 mm × 0.1 = 0.1 cm
1 millimeter = 0.1 centimeters.
Real-world example
10 mm × 0.1 = 1 cm
10 millimeters = 1 centimeter.
Conversion table
| Millimeter (mm) | Centimeter (cm) |
|---|---|
| 1 mm | 0.1 cm |
| 5 mm | 0.5 cm |
| 10 mm | 1 cm |
| 21.0975 mm | 2.10975 cm |
| 42.195 mm | 4.2195 cm |
| 100 mm | 10 cm |
Reverse conversion: Centimeter to Millimeter
0.1 cm × 10 = 1 mm
0.1 centimeters = 1 millimeter.
millimeters = centimeters × 10
For a page dedicated to this direction, see Centimeter to Millimeter.
Millimeter vs. Centimeter
| Aspect | Millimeter | Centimeter |
|---|---|---|
| Family | SI derived (metric prefix) unit | SI derived (metric prefix) unit |
| Typical use | Engineering drawings and manufacturing tolerances worldwide (including in the US) | Everyday small-object and body measurement (height, clothing sizes) outside the US |
| Where it's used | Standard small/precision length unit worldwide, including in US engineering and manufacturing | Standard small-length unit worldwide except the US |
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.
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.
Millimeter — sources
- BIPM SI Brochure — SI prefixes — Defines 'milli-' as the prefix for 10⁻³.
Centimeter — sources
- BIPM SI Brochure — SI prefixes — Defines 'centi-' as the prefix for 10⁻².
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many centimeters are in 1 millimeter?
1 millimeter equals 0.1 centimeters, using the exact defined conversion factor rather than an estimate.
How do I convert millimeter to centimeter?
Multiply the millimeter value by 0.1. The converter above does this instantly to whatever precision you set.
How do I convert centimeter back to millimeter?
Use the reverse factor: 1 centimeter equals 10 millimeters. You can also use the swap control in the converter above to flip the direction instantly.
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.
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.
Is the millimeter to centimeter conversion exact?
Yes. Both millimeter and centimeter are defined by fixed standards rather than physical artifacts, so the factor of 0.1 used above is exact to as many digits as you choose to display.
Where is the millimeter still used today?
Standard small/precision length unit worldwide, including in US engineering and manufacturing