Convert centimeters to meters

m = cm ÷ 100

The prefix does all the work: centi comes from the Latin centum, a hundred, and a centimetre is one hundredth of a metre. Moving the decimal point two places to the left is the entire conversion.

The most common place this conversion goes wrong is the body mass index. BMI is weight in kilograms divided by height in metres, squared. Someone 175 cm tall and weighing 70 kg has a BMI of 70 ÷ 1.75² = 22.9. Enter 175 instead of 1.75 and the result is 0.0023 — obviously wrong, but spreadsheets and hand calculations produce it constantly because height is almost always recorded in centimetres.

In 1791 the French Academy of Sciences defined the metre as one ten-millionth of the distance from the North Pole to the equator, measured along the meridian through Paris. Two astronomers, Delambre and Méchain, spent seven years surveying the arc between Dunkirk and Barcelona to pin it down. Their result was slightly off — the Earth is not a perfect sphere — but the platinum bar cut from it in 1799 became the reference anyway.

Since 1983 the metre has had nothing to do with the planet: it is the distance light travels in a vacuum in 1/299,792,458 of a second. The centimetre inherits that precision automatically.

• 50 cm = 0.5 m
• 150 cm = 1.5 m
• 180 cm = 1.8 m
• 250 cm = 2.5 m

For smaller steps the next unit down is the millimetre — see mm to cm.

The SI Brochure published by the International Bureau of Weights and Measures (BIPM) defines the metre — since 1983, by the distance light travels in 1/299,792,458 of a second — and the prefix centi as 10⁻². ISO 80000-1 applies the same prefix rules across every quantity, which is why dividing by 100 works the same way for any unit called centi-.