How to Convert Between Metric and Imperial Length Units

Road signs in miles, a screen size in inches and a plan in millimetres. Conversions between metric and imperial are exact, because the imperial units are defined in metric terms.

The definitions

• 1 inch = 2.54 centimetres
• 1 foot = 12 inches = 0.3048 metres
• 1 yard = 3 feet = 0.9144 metres
• 1 mile = 1,609.344 metres

Examples

Using the Length Converter:

• 5 miles is 8.04672 km.
• 6 feet is 182.88 cm.

Rules of thumb: a kilometre is about 0.62 miles, a metre is a little over a yard, and an inch is about two and a half centimetres.

Using the converter

1. Enter the length.
2. Choose from and to units: mm, cm, m, km, in, ft, yd or mi.
3. Read the result.

Tips

• For heights written as feet and inches, use the height converter, which combines the two parts.
• The results are shown to several decimal places. Round to what makes sense: nobody needs a mile to the micrometre.
• Nautical miles are a different unit, 1,852 metres, and are not included.

Frequently asked questions