Square centimeters

A square centimeter (cm²) is a unit of measurement of area. 1 square centimeter is equal to the area of a square with sides that measure 1 centimeter.

A square area is a measurement made up of two lengths. Square units of area, such as square centimeters, are a result of multiplying two lengths. In the case of square centimeters, each length is measured in centimeters, so multiplying centimeters × centimeters results in cm². The measured area does not need to be in the shape of a square; any area can be calculated, or estimated, as the area made up by some number of unit squares.

For example, a 4 cm × 2 cm rectangle is made up of 8 squares with an area of 1 cm² each. The rectangle therefore has an area of 8 cm²:

Systems of measurement

A square centimeter is a unit of area in the International System of Units (SI), the most widely used system of measurement. Square centimeters are derived from square meters, the SI unit of area. SI makes it relatively easy to convert an SI unit of area, such as square meters, into larger or smaller measurements of area. This is because SI makes use of prefixes that indicate a specific power of 10 by which the base unit, in this case the meter, is modified. For example, the "centi-" prefix indicates 10^-2, so to express an area such as 10 m² in cm² multiply by (10²)², or 10,000. This is because there are 100 centimeters in a meter, and (100 cm)² (since we are talking about area not length) is 10,000 cm².

It can also be useful to know how to convert between different measurements of area, particularly for those who live in the US, since the US primarily uses US customary units of measurement. Below are the relationships between square centimeters, square meters, and some US customary measurements of area.

10,000 cm² = 1 m²

10,000,000,000 cm² = 1 km²

929.0304 cm² = 1 ft²

40,468,564.224 cm² = 1 acre

Note that these conversions are rounded to 3 decimal places, so they are not exact.