## Centimeters

**Abbreviation/Symbol:**

cm

**Wordwide use:**

The centimetre is used worldwide as a measurement of length. There are a few exceptions, most notably the United States, which still primarily uses the U.S. Customary (similar to imperial) system.

**Definition:**

The centimetre is a unit of length in the metric system, equal to one-hundredth of a metre.

1cm is equivalent to 0.39370 inches.

**Origin:**

The metric, or decimal, system of weights and measures was defined and adopted in France in 1795. Using the metre as the basis for length measurements, the system is now used officially across the globe.

John Wilkins was the first person to publicly recognise the need for a universal length measurement, ie a measurement that could be carried out locally to avoid having to have a definition that refereed to a stored reference unit. He proposed using the length of a “seconds pendulum”. - a pendulum that made half an oscillation per second – as he believed this would have a fixed length. It was later found there is a slight difference in this length around the world. Because of this, the Academy of Sciences devised a new measure, 1/10000000 of the distance from the Equator to the North Pole (measured through Paris). This new value was used to create a metal bar stored at the BIPM’s headquarters known as the “international prototype meter”. This standard has since been superseded by more accurate measures –first by the 11th conference of weights and measures, who defined the meter as “1,650763.73 wavelengths of the orange-red emission line of a krypton-86 atom in a vacuum”. Most recently, in 1983, the 17th conference defined the meter as “the distance travelled by light in a vacuum in 1/299792458 of a second”. From this we derive the centimetre as the distance travelled by light in a vacuum in 1/2997924580 of a second.

Defined at the 17th Conférence Générale des Poids et Mesures (CGPM)

The origin of centimeters can be traced back to the French Revolution in the late 18th century. During this time, there was a need for a standardized system of measurement that would be universally accepted and easily understood. The French Academy of Sciences took on the task of creating such a system, and in 1791, they introduced the metric system.

The metric system was based on decimal units, with the meter as the fundamental unit of length. The meter was defined as one ten-millionth of the distance from the North Pole to the equator, passing through Paris. However, the meter was considered too large for everyday use, so it was divided into smaller units, including the centimeter. The centimeter was defined as one-hundredth of a meter, making it a convenient unit for measuring smaller lengths. It quickly gained popularity not only in France but also in other countries that adopted the metric system. The simplicity and ease of conversion within the metric system made centimeters a practical choice for various applications, such as measuring lengths in science, engineering, and everyday life..

**Common references:**

A United States nickel (5 cent) coin is approximately 2cm diameter.

The cornea of a human eye is approximately 1.15cm (11.5mm) diameter.

One imperial foot is equal to approximately 30.5cm.

1 inch, 2.54 cm

1 metre, 100 cm

30 cm is approximately equal to 1 foot (actually 11.81 inches)

A standard number 2 pencil is 19cm long when new

An average mug from Ikea is about 10cm tall

Theaveragebody.com reports that the palm of an average male is 8.4cm wide and an average female hand is 7.4cm wide

**Usage context:**

The centimetre is used worldwide as a measurement of length. There are a few exceptions, most notably the United States, which still primarily uses the U.S. Customary (similar to imperial) system.

Centimeters are a commonly used unit of measurement in various contexts due to their versatility and ease of use. One of the primary usage contexts for centimeters is in the field of construction and engineering. Centimeters are often used to measure the dimensions of objects, such as the length, width, and height of buildings, furniture, or other structures. This allows for precise and accurate calculations when planning and designing projects.

Centimeters are also frequently used in the field of science, particularly in laboratory settings. Scientists use centimeters to measure the size of specimens, the distance between objects, or the volume of liquids. This is crucial for conducting experiments and recording data with precision.

In addition, centimeters are commonly used in the fashion and textile industry. They are used to measure body dimensions for clothing sizing, ensuring a proper fit for customers. Centimeters are also used in the production of fabrics, where the length and width of materials need to be accurately measured and cut.