Length Converters

How long, tall or far something is — millimeters, inches, feet, centimeters, meters, kilometers and miles.

Converters

Choose a converter

• Feet to Centimeters ft → cm
• Centimeters to Inches cm → in
• Inches to Centimeters in → cm
• Meters to Feet m → ft
• Feet to Meters ft → m
• Kilometers to Miles km → mi
• Miles to Kilometers mi → km
• Millimeters to Inches mm → in
• Inches to Millimeters in → mm
• Centimeters to Feet cm → ft
• Inches to Feet in → ft
• Feet to Inches ft → in

Background

What length units measure

Length units measure distance in a straight line. The inch, the foot and the mile have all been defined in metric terms since 1959 — exactly 2.54 cm, 0.3048 m and 1609.344 m — so converting from them into metric is exact, and only the reverse direction needs rounding.

Guide

Decimal feet, feet and inches, and miles

Converters give decimal answers, and length is where that trips people up most. 5.5 ft is 5 ft 6 in, not 5 ft 5 in: the part after the point is a fraction of a foot, and there are 12 inches in a foot, not 10.

Rulers, drill bits and wrenches in the US are marked in fractions of an inch. Type a fraction as a decimal — 3/8 in is 0.375 — and to read a decimal inch answer as a fraction, multiply the part after the point by 16 and round.

For a height, convert the whole thing in one go. Turn 5 ft 10 in into 70 inches, or about 5.833 feet, first — converting the feet and the inches separately and adding the results is where slips creep in.

The mile on these pages is the international mile, exactly 1609.344 m. The nautical mile used at sea and in the air is a different unit, exactly 1852 m, and none of these pages convert it.

Reference

Length units on this site

Every converter here calculates through meters, so a pair and its reverse always agree. The full list of factors and the standards behind them is on the methodology page.