Convert between common units in seconds. Choose a category, type a value and pick the units. It covers length, weight, area, volume and speed, with metric, imperial and US units.
How it works
Every unit is stored as a multiple of a base unit (metre, kilogram, square metre, litre or metre per second). To convert, the value is multiplied by the factor of the starting unit and divided by the factor of the target unit. For example, one mile is 1,609.344 metres and one kilometre is 1,000 metres, so one mile is 1.609344 km.
For temperature, use our temperature converter.
Example
5 miles = 5 × 1,609.344 ÷ 1,000 = 8.04672 kilometres. 150 pounds = 68.0389 kilograms.
Frequently asked questions
How many kilometres are in a mile?
One mile is exactly 1.609344 kilometres.
What is the difference between US and UK gallons?
A UK (imperial) gallon is about 4.546 litres. A US gallon is about 3.785 litres.
Is the conversion exact?
It uses the internationally defined conversion factors, rounded to ten significant figures.
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Conversions use standard factors. Check critical measurements.