Miles to Inches Converter

The international mile is exactly 1,609.344 meters, or 1.609344 kilometers. It descends from the Roman mile of a thousand paces and remains the standard road distance in the United States and the United Kingdom.

Road signs and speed limits, distance markers on highways, running and cycling events and aviation track distances are quoted in miles in those countries. Nautical miles are separate and longer.

Since the mile is defined as 1,609.344 meters exactly, converting to kilometers or feet is exact arithmetic; only the printed result is rounded. A value converted to kilometers and back can return with a changed last digit.

The common error is using a statute mile where a nautical mile is meant, which understates the intended distance by about thirteen percent. Miles also measure length, not area or speed.

Miles measure road distance, kilometers do the same on metric roads, and nautical miles measure sea and air distance. A nautical mile is longer than a statute mile, so a flight quoted in the wrong one is misread by roughly thirteen percent.

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.