Unit Converter
Convert length, weight, volume, area, speed, temperature and time between metric, imperial and UK units, using exact conversion factors.
Convert Any Unit
Pick a category, type a value and choose your units. You’ll see the answer plus the same measurement in every other unit in that category.
Unit Converter
From miles and stones to litres and hectares.
How it Works
Converting units in four steps
Choose a Category
Select length, weight, volume, area, speed, temperature or time to load the right units.
Enter a Value
Type the amount you want to convert. Decimals and negative numbers are accepted.
Pick Your Units
Choose the unit you have and the unit you want. Use the swap button to reverse them.
Read the Result
See the answer, the reverse conversion, and the same value in every other unit in the category.
Common UK Conversions & Formulas
The metric and imperial equivalents that come up most often in everyday life, from recipes and road signs to DIY and travel.
| Category | Imperial / UK Unit | Metric Equivalent | Reverse |
|---|---|---|---|
| Length | 1 inch | 2.54 cm | 1 cm = 0.3937 in |
| Length | 1 foot | 30.48 cm | 1 m = 3.2808 ft |
| Length | 1 yard | 0.9144 m | 1 m = 1.0936 yd |
| Length | 1 mile | 1.6093 km | 1 km = 0.6214 mi |
| Weight | 1 ounce | 28.3495 g | 100 g = 3.5274 oz |
| Weight | 1 pound | 0.4536 kg | 1 kg = 2.2046 lb |
| Weight | 1 stone (14 lb) | 6.3503 kg | 10 kg = 1.5747 st |
| Volume | 1 UK pint | 568.26 ml | 1 L = 1.7598 UK pints |
| Volume | 1 UK gallon | 4.5461 L | 1 L = 0.22 UK gal |
| Volume | 1 US gallon | 3.7854 L | 1 UK gal = 1.2009 US gal |
| Area | 1 acre | 0.4047 ha | 1 ha = 2.4711 acres |
| Area | 1 square foot | 0.0929 m² | 1 m² = 10.7639 sq ft |
| Speed | 1 mph | 1.6093 km/h | 1 km/h = 0.6214 mph |
| Speed | 1 knot | 1.852 km/h | 1 knot = 1.1508 mph |
| Temperature | °F = (°C × 9/5) + 32 | °C = (°F − 32) × 5/9 | K = °C + 273.15 | ||
Unit Conversion FAQ
Answers to the most common questions about converting between metric, imperial and UK units.
Multiply the number of miles by 1.609344. For example, a 26.2 mile marathon is about 42.16 km. To go the other way, divide kilometres by 1.609344, or multiply by 0.6214.
There are exactly 14 pounds in one stone, and one stone is about 6.35 kg. So 10 stone equals 140 lb, or roughly 63.5 kg.
A UK (imperial) gallon is 4.54609 litres, while a US gallon is 3.785 litres, so the UK gallon is about 20% larger. The same applies to pints: a UK pint is about 568 ml and a US liquid pint is about 473 ml.
Multiply the Celsius temperature by 9/5 (or 1.8) and add 32. The formula is °F = (°C × 9/5) + 32. For example, 20°C is 68°F. To convert Fahrenheit to Celsius, subtract 32 and multiply by 5/9.
The converter uses the internationally agreed exact definitions, such as 1 inch = 25.4 mm, 1 pound = 0.45359237 kg and 1 mile = 1,609.344 m. You choose how many decimal places to show, so any rounding is only in the display.