Length Converter — cm to Inches, Meters to Feet, km to Miles
Convert length units online free — centimeters to inches, meters to feet, kilometers to miles and 20+ more units. Includes Indian units (bigha, biswa) and nautical miles. Instant, no sign-up.
Last updated: June 2026
About this tool
Convert any length instantly
Length is the measurement we convert most often — between the metric units the world mostly uses and the imperial units common in the US and UK, or between everyday scales and the very large and very small. This length converter puts all the common units on one screen: change any one and the rest follow instantly, so you can read your value in metres, feet, miles or inches at a glance.
The metric side covers kilometres down to nanometres, and the imperial side covers miles, yards, feet and inches, all linked by their exact international definitions — a foot is precisely 0.3048 metres and a mile is exactly 1.609344 kilometres. For specialist needs the converter also includes the nautical mile (1,852 metres, used in aviation and shipping) and astronomical distances: the astronomical unit (the average Earth–Sun distance) and the light year.
Because every field is live, the tool is great for quick checks — converting a running distance, a room dimension, a flight altitude or a height — and for learning how the units relate. Results are rounded for readability while the calculation itself uses full-precision factors. Everything runs in your browser with no account and nothing uploaded, so it's fast, free and private to use as often as you need.
How it works
Three quick steps — no account, nothing uploaded to a server.
Type a value
Enter your measurement in any unit's box.
See every unit
All the other units convert at the same instant.
Copy or compare
Read your value across metric, imperial and more.
FAQ
Frequently asked questions
How do I convert metres to feet?
One metre equals about 3.28084 feet, since a foot is defined as exactly 0.3048 metres. Enter your value in the Metre box and the Foot box updates instantly — for example, 10 metres is 32.808 feet. The conversion is exact because the foot has a fixed metric definition.
How many kilometres are in a mile?
One mile equals exactly 1.609344 kilometres, so to convert miles to kilometres you multiply by roughly 1.609. A 5-mile run is about 8.05 kilometres. Type into the Mile box and the Kilometre box fills in automatically.
What units does the length converter support?
It covers the metric scale (kilometre, metre, centimetre, millimetre, micrometre and nanometre), imperial units (mile, yard, foot and inch), the nautical mile used in aviation and shipping, and astronomical distances (the astronomical unit and the light year) for science work.
Is the conversion exact?
Yes for defined relationships — the metre-to-foot, mile-to-kilometre and inch-to-centimetre factors are exact by international definition. Displayed results are rounded for readability, but the underlying calculation uses the full-precision factors.
How long is a light year?
A light year is the distance light travels in one year — about 9.46 trillion kilometres (9.46 × 10¹² km). Enter 1 in the Light year box to see it expressed in kilometres and metres, which is a striking way to grasp astronomical scale.