cm to mm

There are 10 millimeters (mm) in 1 centimeter (cm). Both centimeters and millimeters (also spelled centimetre and millimetre) are part of the metric system of measurement. They are also both related to the meter (m), or metre, which is the base unit of length in the International System of Units (SI), the modern form of the metric system.

Convert cm to mm

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


How many cm in a mm

There are 0.1 centimeters in 1 millimeter, or:

0.1 cm = 1 mm

How many mm in a cm

There are 10 millimeters in 1 cm, or:

10 mm = 1 cm

cm to mm conversion

To convert centimeters to millimeters, multiply by 10. To convert mm to cm, divide by 10.

cm to mm formula

The formula for converting centimeters to millimeters is:

Similarly, the formula for converting millimeters to centimeters is:

Both millimeters and centimeters are related to meters, where the "milli-" and "centi-" prefixes indicate that they are and meters respectively. Thus:

1 m = 100 cm = 1000 mm

Below are some cm to mm conversion examples:


1. Convert 157 cm to mm:

157 cm × 10 = 1570 mm

2. Convert 8872 mm to cm:

8872 mm ÷ 10 = 887.2 cm

What is a centimeter

A centimeter (cm) is a unit of measurement of length in the International System of Units.

Centimeter definition

A centimeter is defined as of a meter. The meter is defined as the length of the path traveled by the speed of light in vacuum in of a second.

Centimeter history

The centimeter as a unit of measurement originated with the introduction of the metric system in 1795. The metric system was developed to replace the systems of measure at the time since they were not practical. The meter and the kilogram became the standard measures of length and mass in all of France in 1799. In the middle of the 19th century, James Clerk Maxwell developed a system comprised of base units (such as the meter and kilogram) and derived units, which are defined in terms of the base units.

In the metric system, prefixes are used alongside base units to denote a power of 10. For example, the prefix "centi-" denotes , so "centimeter" indicates one hundredth of a meter. The definition of the meter (and thus that of the centimeter) has changed throughout history with the goal of reducing uncertainty. In 1899, it was defined in terms of the distance between two lines at the melting point of ice on a standard bar made of platinum and iridium; this was called the International Prototype Metre. The meter was later redefined using the wavelengths, and then again in terms of the speed of light. Each subsequent definition essentially kept the same measured length of the meter, while making its definition more robust.

Current use of the centimeter

As an SI unit, the centimeter is used widely throughout the world. For example, a typical ruler is 30 centimeters (12 inches) long. Centimeters are usually used for smaller measurements of length that are still relatively easy to conceive. Another common use of the centimeter is with the measurement of height. With the exception of countries such as the United States, Myanmar, and Liberia, most countries around the world measure height in terms of centimeters.

What is a millimeter

A millimeter (mm) is a unit of measurement of length in the International System of Units.

Millimeter definition

A millimeter is defined as of a meter. The meter is defined as the length of the path traveled by the speed of light in vacuum in of a second.

Millimeter history

The history of the millimeter (as well as centimeter) follows that of the meter, as described in the section above. Its definition changed from being based on a pendulum length, the distance between the North Pole and the Equator along the meridian through Paris, a physical prototype, wavelengths of the krypton-86 atom, and the speed of light.

Current use of the millimeter

The millimeter, like any other SI unit of measurement, is widely used throughout the world. It is used for very small measurements of length such as the thickness of a piece of paper, the diameter of the wire used to make a paperclip, the width of a sewing needle, and more.

Centimeter to millimeter conversion table

The table below shows some common cm to mm conversions:

Centimeter Millimeter
0.01 0.1
0.1 1
1 10
2 20
3 30
5 50
10 100
20 200
50 500
100 1,000
1,000 10,000

Difference between cm and mm

A centimeter differs from a millimeter only in size. Both are measurements of length that are defined in terms of the SI base unit of length, the meter. A centimeter is one-hundredth of a meter, while a millimeter is one-thousandth of a meter. Generally, measurements in centimeters and millimeters are both discernible to the human eye, but millimeters are typically used to measure much smaller objects than centimeters. Usually, we decide which unit to use based on the size of the object. For example, height is commonly measured in centimeters. A height of 150 cm is slightly easier to visualize than a height of 1,500 mm.