Length Converter

Convert any length unit to any other — inches, feet, yards, miles, millimetres, centimetres, metres and kilometres.

Length is the most converted quantity in home improvement — plans in feet, materials in metres, distances in miles or kilometres. This converter covers all eight units, exactly.

Pick the units, enter the value, and the conversion follows.

Formula

Convert via metres (the base unit): in × 0.0254 | ft × 0.3048 | yd × 0.9144 | mi × 1609.344 mm × 0.001 | cm × 0.01 | m × 1 | km × 1000 Then divide by the target unit's factor. Intermediates are never rounded — only the displayed result is rounded.

All lengths are converted to a single unit before the calculation: 1 ft = 0.3048 m, 1 in = 25.4 mm, 1 ft² = 0.09290304 m², 1 yd² = 9 ft². Material quantities are rounded up — you cannot buy part of a tile, plank or bag.

How to use this calculator

Enter the length value.
Choose the unit it is in, and the unit to convert to.
Read the converted length (and its metre value).
Use the Copy results button to copy the answer.

Worked example

Value	1 mile
To kilometres	1609.344 ÷ 1000 = 1.6093 km
100 ft to metres	100 × 0.3048 = 30.48 m
1 km to miles	1000 ÷ 1609.344 = 0.6214 mi

Check it by hand: every step above uses the formula in the box. If your numbers match the example inputs but the calculator gives a different answer, please report it via the contact page.

Frequently asked questions

How many kilometres are in a mile?

1.609344 km (exact). So 1 mile is 1.6093 km, and 1 km is 0.6214 miles.

How many metres are in a yard?

Exactly 0.9144 m. A yard is defined as 0.9144 metres — the conversion is exact.

How many millimetres are in an inch?

Exactly 25.4 mm. The inch is defined as 25.4 mm — the conversion is exact.

Which length unit should I use?

Millimetres for small work, metres for rooms, kilometres for distances in metric countries; inches, feet, yards and miles in the US. This converter moves between all eight.

Related calculators

Estimates only. Results are for planning. Measure twice, confirm box coverage and tile sizes on the packaging you buy, and follow the manufacturer's instructions. See the disclaimer.