1 centimeters to millimeters
10.0 mm
1 cm = 10.0 mm.
millimeters
10.0mm
1 cm = 10.0 mm
In short
How many millimeters is 1 centimeters?
1 cm = 10.0 mm. 1 centimeter = 10.000000 millimeters, so the working is 1 × 10.000000 = 10.0.
The working
The factor below is an exact definition rather than a measurement, so nothing is approximated in the arithmetic. The only rounding on this page happens where a number is displayed.
1 centimeter = 10.000000 millimeters 1 × 10.000000 = 10.0
How much precision do you need?
Each row is the same answer cut at a different number of decimals, with what that choice costs you. Pick the shortest row whose error is smaller than whatever you are measuring with.
| Rounded to | Answer (mm) | Off by |
|---|---|---|
| Whole number | 10 | exact |
| 1 decimal | 10.0 | exact |
| 2 decimals | 10.00 | exact |
Round trip: take 10.0 mm back the other way and you land on 1.0000 cm — a drift of 0.0000 cm. That gap is the rounding, not the conversion.
What 1 cm looks like
1 cm
One centimetre is 10 mm, which is why drawings quote 25 mm rather than 2.5 cm.
Frequently asked questions
What is 1 centimeters in millimeters?
1 centimeters is 10.0 millimeters. 1 centimeter = 10.000000 millimeters, so the working is 1 × 10.000000 = 10.0.
How accurate is 10.0 mm?
Rounding to 10.0 mm and converting straight back gives 1.0000 cm, a drift of 0.0000 cm from the 1 you started with. The factor itself is exact; every bit of that difference comes from the rounding, not the conversion.
Nearby values
Any value at all
Centimeters to Millimeters Converter
Convert cm to mm — and how a drawing states its unit once, not per dimension.
Open the centimeters to millimeters converter →