Length Converter
Convert between 16 length units — metric, imperial, nautical and astronomical.
Converted locally in your browser — nothing is uploaded.
- Every unit updates at once — type a value and read the equivalent in all the others.
- Covers nm, μm, mm, cm, m, km; inch, foot, yard, mile; fathoms, chains and furlongs; nautical miles; and astronomical units/light years.
- Popular-conversion shortcuts and a full one-tap reference table for the current unit.
- Runs in your browser, works offline once loaded, no ads in the result.
Why this is private
- Converted locally in your browser — nothing is uploaded.
- Open your browser's DevTools → Network tab while using this tool — you won't see a request carrying your input, because it never leaves your device.
- Nothing you enter is uploaded to a server or shared with us — the processing happens entirely on your device.
Overview
Converts length and distance across 16 units — nanometers through light years, covering metric, imperial, nautical and astronomical scales.
How to use it
- 1Enter a value and pick its unit.
- 2Pick the unit to convert to, or use a popular-conversion shortcut.
- 3The result updates instantly, both ways.
- 4Open the reference table to see the value in every other unit at once.
Frequently asked questions
What people use it for
Convert a height between cm and feet/inchesRead 175 cm as 5 ft 8.9 in for a form that wants imperial.
Check a screen or furniture measurementTurn a listing in inches into centimetres to see if it fits.
Convert a running or driving distanceSwitch a route between kilometres and miles, or a marine distance in nautical miles.
Read an overseas spec sheetConvert millimetre tolerances to inches, or the reverse.
Convert an astronomical distanceTurn a distance in light years or astronomical units into kilometers for a science reference.
Related tools
All converters toolsWeight ConverterConvert between 12 weight units, including troy ounces, carats and US/UK tons.Area ConverterConvert between 10 area units — square inches through square miles.Speed ConverterConvert between km/h, mph, m/s, knots and Mach.Temperature ConverterConvert between Celsius, Fahrenheit, Kelvin and Rankine.
Ready to use Length Converter?
Length Converter