Centimeter (cm)
A centimeter is one hundredth of a meter: 1 cm = 0.01 m. One centimeter contains exactly 10 millimeters.
- Symbol
- cm
- System
- Metric
- Meter value
- 0.01 m
- Singular
- centimeter
- Plural
- centimeters
- Aliases
- centimetre, centimetres
What a centimeter measures
The centimeter is convenient for hand-sized and tabletop measurements. It is a decimal subdivision of the meter, so moving between centimeters and meters changes the decimal point by two places.
- Ten millimeters make exactly 1 centimeter.
- A typical 30-centimeter classroom ruler is just under 12 inches long.
- One meter contains exactly 100 centimeters.
- One centimeter is approximately 0.3937 inch.
Where centimeters are used
Definition and standardization
The prefix centi means one hundredth. The centimeter therefore inherits its value from the SI definition of the meter.
The correct symbol is cm, with both letters lowercase.
Although the meter is the SI base unit, centimeters are practical decimal multiples for many everyday measurements.
Tools used to measure centimeters
- Metric ruler for short lengths
- Tape measure for body and object dimensions
- Caliper when sub-millimeter resolution is needed
Common mistakes
- Confusing centimeters with millimeters when counting ruler marks
- Using 2.5 instead of the exact 2.54 when converting inches to centimeters
- Treating a measured value as more precise than the ruler markings
Centimeter questions
How many centimeters are in a meter?
There are exactly 100 centimeters in 1 meter.
How many centimeters are in an inch?
One inch equals exactly 2.54 centimeters.
Are centimeters part of SI?
A centimeter is a decimal submultiple of the SI base unit meter, formed with the SI prefix centi.