There are many units of length. The most common ones are Meter (m), Centimeter (cm), Kilometer (km), and Foot (ft). We often use the abbreviations MM and CM for meters and centimeters. However, it is very important to know that these two abbreviations have different meanings. Therefore, in this article, we will learn about the difference between MM and CM.

## Summary Table

MM |
CM |

MM is the abbreviation of millimeter. | CM is the abbreviation of centimeter. |

One MM is equal to 0.1 cm. | One CM is equal to 10 mm. |

MM is a unit of length. | CM is a unit of length as well as a unit of area. |

## Definitions

The International System of Units (SI) is the modern system of units. It was established in 1960. In 1960, the General Conference on Weights and Measures (CGPM) decided to redefine some of the units. This is how SI was established. Before that, many countries had their own system of units. However, in 1960, it was decided that all countries should use SI as their system of units.

After 1960, many new units were added to SI. For example, Terahertz (THz), Picoohm (pOhm), Femtoohm (fOhm), etc. Many other changes were also made to existing units such as addition of prefixes for smaller numbers and the removal of prefixes for larger numbers. All these changes were approved by the 11th CGPM which was held in 1967.

The units of SI are derived from those of the metric system. In fact, there are only 7 base units in SI whereas there are 8 base units in the metric system. In SI, meter is the base unit of length and kilogram is the base unit of mass. On the other hand, in the metric system, meter is the base unit of length and gram is the base unit of mass. The SI units are all defined in terms of these base units.

MM is the abbreviation for millimeter. It is a unit of length in SI. 1 mm = 10-3 m. In other words, 1 mm = 0.001 m.

CM is the abbreviation for centimeter. It is also a unit of length in SI. 1 cm = 10-2 m. In other words, 1 cm = 0.01 m.

The word milli comes from Latin word mille which means thousand and the word centi comes from Latin word centum which means hundred. So, we can say that MM and CM are derived from these Latin words mille and centum respectively (1 m = 1000 mm and 1 m = 100 cm).

## CM vs MM

In many situations, we use the abbreviation mm instead of cm due to typing error (typing error happens when you type fast). However, this may cause serious problems if we are working with electronics or if we are measuring a certain object. In electronics, the units of electrical current are in Ampere (A) and the units of resistance are in Ohm (Ω). If we use cm instead of mm, it will cause a big difference in calculations. For example, if we have to calculate the resistance of a wire which is 2.5cm long, then the value of resistance will be different if we use mm or cm.

The main difference between MM and CM is that mm is a unit of length whereas cm is a unit of length as well as a unit of area. In fact, 1cm2 is equal to 10mm2. So, if we are measuring a flat surface, then we must use cm and not mm.

Generally, MM is more popular than CM. However, there are also many other units of length that are more popular than mm and cm. For example, km (kilometer), mile (mile), etc. So, we can say that it depends on the unit of length that we are talking about.

For example, In the United States, mm is more popular than cm. In the United States, mm is often used to measure the length of small objects such as wires and cables. However, cm is more popular than mm in many other countries such as Canada, India, Pakistan, etc.

We can use MM and CM in many places. For example, we can use them to measure the length of wires, cables, computer chips, etc. We can also use them to measure the height of a person or animal. In some cases, we can also use them to measure the height of buildings.

## How to convert MM to CM?

To convert mm to cm, we have to divide the number of mm by 10. So, for example, if we want to convert 6 mm into cm, we have to divide 6 by 10. The result is 0.6 cm. This means that 6 mm = 0.6 cm.

To convert cm into mm, we have to multiply the number of cm by 10. So, for example, if we want to convert 2 cm into mm, we have to multiply 2 by 10. The result is 20 mm (2 × 10 = 20). This means that 2 cm = 20 mm.

As you can see, the process of converting mm into cm is opposite to the process of converting cm into mm.

## How to Remember the Difference between MM and CM?

It is very easy to remember the difference between mm and cm. As mm is a unit of length, we can convert it into meters using multiplication. On the other hand, cm is a unit of length as well as a unit of area. Therefore, we can convert it into square meters. In order to remember the difference between mm and cm, we can use the following phrase:

Meters is made up of Millimeters whereas Centimeters are made up of Square Meters.