CM to MM Calculator — Centimeters to Millimeters
Convert centimeters to millimeters instantly — and also see the equivalent in meters, inches and kilometers for a complete reference.
cm
10 cm
- 1
Centimetres → millimetres (× 10)
10 × 10 = 1001 cm = exactly 10 mm — the milli- prefix means 1/1000, centi- means 1/100 - 2
Metres (÷ 100)
10 ÷ 100 = 0.1 - 3
Inches (÷ 2.54)
10 ÷ 2.54 = 3.93701
How does this calculator work?
Multiply cm by 10 to get mm — exact metric conversion. 1 cm = 10 mm. Reverse: divide mm by 10 to get cm. Examples: 2.5 cm = 25 mm; 100 cm = 1000 mm = 1 m. No rounding needed.
Formula
How this is calculated
Both millimeters and centimeters are SI metric units. The prefix "milli" means 1/1000 and "centi" means 1/100, so 1 cm = 10 mm exactly. To convert centimeters to millimeters, multiply by 10; to go from millimeters to centimeters, divide by 10. Like all SI conversions, this is exact — no approximation is involved.
Millimeters are commonly used for precision engineering, jewelry sizing, medical measurements and product dimensions where centimeters would leave a trailing decimal. A 2.5 cm gap is more clearly stated as 25 mm in technical contexts. Conversely, centimeters are more convenient for everyday measurements such as clothing sizes, screen dimensions and room widths.
The secondary table also shows meters (divide by 100) and inches (divide by 2.54) so you can cross-reference across metric and imperial systems in one place.
Frequently asked questions
1 centimeter = exactly 10 millimeters. Other examples: 5 cm = 50 mm; 2.5 cm = 25 mm; 0.1 cm = 1 mm.
Move the decimal point one place to the right (multiply by 10): 3.7 cm → 37 mm; 12.5 cm → 125 mm; 0.3 cm → 3 mm.
Use mm for precision contexts (engineering, jewelry, medical) where values below 1 cm would need a decimal in cm. Use cm for clothing, height and general room measurements where the larger scale is more intuitive.
Also known as
TG we-Calculate Editorial Team. (2026). CM to MM Calculator — Centimeters to Millimeters [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/cm-to-mm-conversion-calculator
TG we-Calculate Editorial Team. "CM to MM Calculator — Centimeters to Millimeters." TG we-Calculate. 2026. https://we-calculate.com/calculator/cm-to-mm-conversion-calculator.
TG we-Calculate Editorial Team, "CM to MM Calculator — Centimeters to Millimeters," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/cm-to-mm-conversion-calculator
@misc{wecalculate_cm_to_mm_conversion_calculator, title = {CM to MM Calculator — Centimeters to Millimeters}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/cm-to-mm-conversion-calculator}}, year = {2026}, note = {TG we-Calculate} }
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