Inches to Feet 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 foot is exactly 0.3048 meters, or twelve inches. United States survey work has used a separate survey foot, defined as 1200/3937 meters and equal to about 0.3048006 meters.

Aviation uses feet for altitude and flight levels worldwide, even in countries that measure road distance in kilometers. Building heights, room dimensions, timber and, in some places, body height are also quoted in feet.

The metric conversion is exact, since the foot is defined as 0.3048 meters, and the reverse is exact too. A displayed result is rounded to six decimal places at most, so a round trip can differ in the final digit.

The common slip is assuming a foot is close to a third of a meter when it is slightly longer, so rough mental division undershoots. Feet also belong to length, while square feet measure area and cubic feet measure volume.

The foot competes with the meter for height and building dimensions and with the inch for small spans. Because one meter is a little over three feet, treating a meter figure as feet overstates a dimension more than threefold.