📏 Length Converter

From a DIY project in inches to a distance in miles on a US road sign: convert any length exactly to the unit you need. This calculator covers both the metric system (millimetre to kilometre) and the imperial/US system (inch, foot, yard, mile).

Result 328.084 ft

Formula

Result = (value × from-factor) ÷ to-factor, relative to the metre

Every length unit has a fixed, exact conversion factor to metres (for example 1 inch = 0.0254 m, 1 mile = 1609.344 m). The calculator converts to metres first and then from metres to the target unit, so every combination works without a separate formula per unit pair.

Steps

  1. 1Enter the value you want to convert.
  2. 2Choose the unit to convert from and to.
  3. 3Read the exact result instantly.

Length units in metres

UnitIn metres
1 millimetre (mm)0.001
1 centimetre (cm)0.01
1 metre (m)1
1 kilometre (km)1,000
1 inch0.0254
1 foot (ft)0.3048
1 yard (yd)0.9144
1 mile1,609.344

All factors are internationally defined as exact values, so there is no rounding error in the conversion.

commonMistakes

  • Confusing feet and yards: 1 yard equals 3 feet, they are not the same.
  • Assuming a "mile" is the same as a nautical mile; a land mile is 1609.344 m, a nautical mile is 1852 m.
  • Swapping the comma and period as decimal separators between countries (1,000 can mean either one thousand or one point zero).

useCases

  • Converting a furniture size from a US webshop into centimetres.
  • Converting travel distances on US or UK road signs (miles) into kilometres.
  • Converting construction or DIY drawings in inches and feet into the metric system.