mm to cm

There are 10 millimeters in 1 cenitimeter. Both millimeters and centimeters are units of length in the metric system and are related to the meter, the base unit of length in the International System of Units (SI).

mm to cm conversion

The following converter can convert from millimeters to centimeters or centimeters to millimeters. Just enter a value in either millimeters or centimeters to convert between the two.


mm to cm conversion explanation

Both millimeters and centimeters are fractions of a meter. "Milli-" comes from the Latin, "mille," meaning one-thousand, and centi comes from "centum" meaning hundred. In the International System of Units, they signify one thousandth and one hundredth respectively.

There are a number of other prefixes in SI aside from centi- and milli-, all of which are used to indicate that a unit is either a multiple or a fraction of a power of 10 of the base unit. We can see this relationship by rewriting the relationship between 1 meter and its corresponding number of centimeters and millimeters:

1 m = 100 cm = 1000 mm


1 × 100 m = 1 × 102 cm = 1 × 103 mm

From this we can see that all of these units are related by a power of 10. Thus, to convert from mm to cm (or any other multiple/fraction of a meter), we just need to know what power of 10 the prefix represents, and either multiply or divide, depending whether the prefix indicates that the unit is larger or smaller than the base unit.

Since a centimeter is larger than a millimeter by a factor of 10, we need to divide by 10 to convert a value that is in millimeters to centimeters. Conversely, if we have a value in centimeters, we need to multiply by 10 to convert it to millimeters.


1. Convert 1828.8 mm to cm:

1828.8 mm ÷ 10 = 182.88 cm

2. Convert 22.7 cm to mm:

22.7 cm × 10 = 227 mm