Inches to Centimeters Converter

An inch is exactly 2.54 centimeters, or 25.4 millimeters. Twelve inches make one foot and thirty-six make a yard, so the inch sits inside two larger imperial units.

Screen and tyre sizes are given in inches, as are pipe and hose diameters, wrench openings and the diagonal of a television. Rainfall is still recorded in inches in some countries.

Because the inch has an exact metric value, converting to millimeters or centimeters introduces no error beyond display rounding. This site shows at most six decimal places, so very small fractions may appear shortened.

A frequent mistake is reading a pipe size as an exact outside diameter when trade sizes are nominal. Another is converting inches to centimeters and then labelling the answer millimeters.

People confuse inches with centimeters most often of all, then with feet. Screen and pipe sizes are inches, while fabric and body measurements may be either, and a twelvefold confusion between inches and feet is the usual consequence of misreading a unit label in practice.

The centimeter is exactly one hundredth of a meter, written 0.01 m, and it is the unit most metric rulers and tape measures are marked in, with ten millimeters to one centimeter.

It appears on clothing labels, school rulers, rainfall reports and body measurements, and in medicine for wound sizes. A person's height is commonly recorded in centimeters on metric forms.

The factor between centimeters and inches is exact: one inch equals 2.54 centimeters. Results on this site are shown with up to six decimal places, so a value converted out and back can end one digit away.

The usual error is reading a millimeter figure as centimeters, which overstates a length tenfold, or treating square centimeters as if they scaled with centimeters rather than with their square.

Centimeters, millimeters and meters divide the same scale: millimeters suit engineering tolerances, centimeters suit height and clothing, and meters suit rooms and buildings. Choosing the wrong unit misplaces the decimal point by ten or a hundred, so the label matters as much as the figure.