Convert cm to mm
Convert cm to mm instantly. 1 cm = 10 mm. Formula, worked examples and a quick reference table.
Last updated
One centimeter equals 10 millimeters. To convert any number of centimeters to millimeters, multiply by 10.
The converter above works in both directions and updates as you type. Below you will find the formula, a worked example and a reference table of common values.
Length conversions come up wherever a measurement crosses a border: a height given in feet and inches on a form that wants centimetres, a running distance recorded in kilometres and compared against miles, a component specified in millimetres and ordered from a supplier working in inches. The conversions themselves are exact — the inch, foot, yard and mile have all been defined in metric terms since 1959 — so any discrepancy comes from rounding, not from the units disagreeing.
cm to mm formula
To go the other way, use centimeter = millimeter ÷ 10.
About these units
The centimetre is a hundredth of a metre. It is the everyday unit for body height and clothing sizes almost everywhere outside the United States, where feet and inches persist.
The millimetre is the working unit of engineering drawings and machining across most of the world, precise enough that dimensions rarely need decimals.
Centimeter is also written centimetre, centimetres and centimeters. Millimeter is also written millimetre, millimetres and millimeters.
Sources
cm to mm conversion table
| Centimeter | Millimeter |
|---|---|
| 1 cm | 10 mm |
| 2 cm | 20 mm |
| 3 cm | 30 mm |
| 5 cm | 50 mm |
| 10 cm | 100 mm |
| 20 cm | 200 mm |
| 25 cm | 250 mm |
| 50 cm | 500 mm |
| 100 cm | 1,000 mm |
| 250 cm | 2,500 mm |
| 500 cm | 5,000 mm |
| 1,000 cm | 10,000 mm |
Frequently asked questions
How many millimeters are in a centimeter? +
There are 10 millimeters in one centimeter.
What is 10 cm in mm? +
10 cm equals 100 mm. Multiply 10 by 10.
How do I convert millimeter back to centimeter? +
Use centimeter = millimeter ÷ 10. The converter above handles both directions, or see our dedicated mm to cm page.
How accurate is this centimeter to millimeter conversion? +
The factor used is 10, carried at full double precision. Where a unit has an exact legal definition the factor is exact rather than approximate. Rounding is applied only to the displayed result, so the answer is never a calculation done on an already-rounded number.
Is there a quick way to estimate cm to mm in my head? +
Multiply by 10. That matches the true factor of 10 exactly, so no adjustment is needed for a mental estimate.