Unit Converters

Cm to Mm Converter

Convert centimeters to millimeters or back with the exact SI rule of 10 mm per cm. Every conversion is precise with no rounding.

Try
Converted length
100 mm

10 centimetres → millimetres

Conversion factor
×10
1 cm equals
10 mm
Conversion factors are exact; rounding may affect the final digit.
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How it's calculated

mm = cm × 10

cm = centimetres, mm = millimetres. Reverse: cm = mm ÷ 10.

Common values

CentimetersMillimeters
1 cm10 mm
2.5 cm25 mm
10 cm100 mm
100 cm1000 mm

Common questions

How many millimeters are in a centimeter?

Exactly 10 millimeters.

How do I convert cm to mm in my head?

Just add a zero, or move the decimal point one place to the right. So 4.7 cm is 47 mm.