Convert

Centimetre to Millimetre

Exact answer: 1 cm = 10 mm (exact – SI decimal prefix)

Centimetre and Millimetre both belong to the Length family. The difference is a decimal prefix, so the factor is a clean power of ten. Length figures range from nanometres in semiconductor manufacturing to astronomical distances, and inch, foot and mile come from a different system of units.

Unit console

Convert units with formula, context and precision

UnitCloud is a local measurement lab for everyday work, engineering, IT, energy, mobility and design. Every conversion shows result, formula, base unit, rounding and the common mistake.

What do you want to convert?

From1 cm

Result10 mm

Factor1 cm = 10 mm

Source basisBIPM SI Brochure · NIST Guide to SI Appendix B

Examples

011 cm = 10 mm

Example value from the reference table. Internal calculation uses stored factors; display output is rounded.

02Common mistake

Inch, foot and mile use fixed factors. Errors usually come from early rounding or from mixing land miles and nautical miles.

03Base unit: m

1 cm = 0.01 m. Then the value is converted through the base unit m into Millimetre.

Table

Centimetre to Millimetre
Centimetre	Millimetre
1	10
2.5	25
10	100
25	250
100	1,000
250	2,500

Formula

1 cm = 0.01 m. Then the value is converted through the base unit m into Millimetre.

Sources

BIPM SI BrochureSI base units, prefixes and official SI context.NIST Guide to SI Appendix BNIST conversion-factor method and non-SI factors.

Related conversions

Inch to Centimetrein → cmLength Centimetre to Inchcm → inLength Millimetre to Centimetremm → cmLength Metre to Centimetrem → cmLength

Search and practice paths

FormulaTableExamplesCommon mistakeEveryday/engineeringExcel/CSVBatch converterPrint view

LengthReading astronomical distances Data rateReading internet speed correctly

Factor origin

Factors come from the stored source family and are not derived from rounded display values.

Rounding rule

UnitCloud keeps calculating with stored factors and rounds only the displayed output by selected precision.

When not to use

Do not use as the sole basis for official, medical, safety-critical or contractual decisions.

Citation

Citation note: UnitCloud, conversion with formula, sources reviewed: September 2026. Length. Source basis: BIPM SI Brochure · NIST Guide to SI Appendix B.

Common questions

What is the factor for Centimetre to Millimetre?

1 cm = 10 mm

Which formula does Centimetre to Millimetre use?

1 cm = 0.01 m. Then the value is converted through the base unit m into Millimetre.

What is the most common mistake?

Inch, foot and mile use fixed factors. Errors usually come from early rounding or from mixing land miles and nautical miles.

When should I verify the result?

Do not use as the sole basis for official, medical, safety-critical or contractual decisions.