CM to Inches Converter
To convert centimetres to inches, divide the number of centimetres by 2.54. One inch is exactly 2.54 cm, so 10 cm is 3.94 inches, 25 cm is 9.84 inches and 100 cm is 39.37 inches. You can also multiply by 0.3937 for the same result.
Use the length converter for any value. Below you will find the formula, a chart from 1 cm to 200 cm, worked examples, tape-measure fractions, everyday UK examples and the mistakes to avoid.
How do you convert cm to inches?
To convert cm to inches, divide the length in centimetres by 2.54. The number 2.54 is not rounded: the inch is defined as exactly 2.54 centimetres, so the formula is exact and only your final rounding adds error.
inches = centimetres / 2.54
The method takes three steps:
- Write down the length in centimetres, for example 25 cm.
- Divide by 2.54: 25 / 2.54 = 9.8425.
- Round to the precision you need: 9.84 in to two decimal places, or about 9 13/16 in on a tape measure.
If you prefer to multiply, use 0.3937 instead: 25 x 0.3937 = 9.8425. Both routes give the same answer, because 1 / 2.54 = 0.393701 to six decimal places.
On a 12 cm ruler, the 10 cm mark sits just short of the 4-inch mark, because 10 cm is 3.94 in.