Length converter
Convert between millimeters, centimeters, meters, kilometers, inches, feet, yards and miles, then watch the tape measure unroll to show what that distance really looks like.
That's 1.8× as long as a guitar, while a door is 1.11× longer. Walking, you would cover that in 1.286 seconds.
What it means
How long is that?
Reference lengths are typical values. The inch, foot, yard and mile are defined exactly in meters (1 inch = 2.54 cm).
Every unit
Your length in every unit
Learn
Three things worth knowing
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Inches to cm in your head
Multiply inches by 2.5 and add a little: 10 inches is about 25 cm (really 25.4). Going back, halve the centimeters and take off a fifth.
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The meter was the Earth
In the 1790s French scientists defined the meter as one ten-millionth of the distance from the North Pole to the equator, measured through Paris. They were off by 0.2 mm.
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A nautical mile is not a mile
A nautical mile is 1,852 m, about 15% longer than a land mile, because it comes from one minute of latitude on the globe rather than from Roman paces.
Shortcuts
Popular length conversions
- cm → in
- in → cm
- m → ft
- ft → m
- km → mi
- mi → km
- mm → in
- in → mm
- m → yd
- yd → m
- cm → ft
- ft → cm
- km → nmi
- nmi → km
- m → in
- in → ft
- µm → mm
- mm → µm
- nm → µm
- AU → km
- ftm → ft
- fur → m
- li → km
- km → li
- verst → km
- km → verst
- league → km
- km → league
- cubit → m
- m → cubit
- hand → cm
- cm → hand
- chain → m
- m → chain
- rod → m
- m → rod
- thou → mm
- mm → thou
- shaku → cm
- cm → shaku
- pc → ly
- ly → pc
Background
About length units
Length is the most converted quantity there is, because two systems are still in daily use. Most of the world measures in meters and centimeters; the United States uses inches, feet and miles.
All of them are now defined from the meter, which since 1983 is the distance light travels in 1/299,792,458 of a second.