About converting centimetres to inches

One inch is exactly 2.54 centimetres. That is a definition rather than a measurement - the international yard and pound agreement of 1959 fixed it - so every conversion on this page is exact arithmetic, not an approximation.

To go the other way, divide by 2.54. For a rough figure in your head, divide the centimetres by 2.5, which is within 2% and usually close enough for clothing and furniture.

Centimetre to Inch reference table

Centimetre Inch
1 cm 0.393701 in
2 cm 0.787402 in
5 cm 1.9685 in
10 cm 3.93701 in
15 cm 5.90551 in
20 cm 7.87402 in
25 cm 9.84252 in
30 cm 11.811 in
40 cm 15.748 in
50 cm 19.685 in
60 cm 23.622 in
75 cm 29.5276 in
100 cm 39.3701 in
150 cm 59.0551 in
180 cm 70.8661 in
200 cm 78.7402 in

Frequently asked questions

How many inches is 30 cm?
11.811 inches, or just under a foot. The conversion is 30 ÷ 2.54.
Why is an inch exactly 2.54 cm?
Because six countries agreed to define it that way in 1959, to end a situation where the American and British inches differed by about two parts in a million. Before that, the inch was defined by physical standards that did not quite agree.
Is anything I enter sent anywhere?
No. The conversion runs inside your browser. Nothing you type is uploaded, stored or logged, and the page keeps working with the network disconnected.

How your data is handled

Everything happens on your device. There is no upload, no storage and no logging. Closing the tab clears everything you entered.