A centimeter is a unit of length in the metric system, equal to one-hundredth of a meter. It is commonly used to measure shorter distances, such as the height of a person or the dimensions of an object. The symbol for centimeter is cm. Centimeters are part of the International System of Units (SI), which is widely used around the world. This system makes it easier to convert between different units, as 1 meter equals 100 centimeters. For example, a standard sheet of paper is typically 21 centimeters wide and 29.7 centimeters long.