Unit converter
Fourteen categories, every unit at once, the formula shown. Type a value, pick the units; the result and the table update as you type.
1 km = 0.621371 mi
1 kilometre in every length unit
| Unit | Value | Symbol |
|---|---|---|
| nanometre | 1000000000000 | nm |
| micrometre | 1000000000 | um |
| millimetre | 1000000 | mm |
| centimetre | 100000 | cm |
| metre | 1000 | m |
| kilometre | 1 | km |
| inch | 39370.1 | in |
| foot | 3280.84 | ft |
| yard | 1093.61 | yd |
| mile | 0.621371 | mi |
| nautical mile | 0.539957 | nmi |
| astronomical unit | 6.68459e-9 | au |
| light-year | 1.057e-13 | ly |
All categories
Length
Metres, kilometres, inches, feet, yards, miles, nautical miles, light-years.
Area
Square metres, hectares, acres, square feet, square kilometres, square miles.
Volume
Litres, millilitres, cubic metres, US and UK gallons, cups, pints, quarts, fluid ounces.
Mass
Grams, kilograms, tonnes, ounces, pounds, stones.
Temperature
Celsius, Fahrenheit, kelvin and Rankine, with the formulas.
Speed
Metres per second, km/h, mph, knots, feet per second.
Time
Seconds, minutes, hours, days, weeks, months, years.
Energy
Joules, kilojoules, calories, kilocalories, watt-hours, kWh, BTU, electronvolts.
Power
Watts, kilowatts, megawatts, horsepower, metric horsepower, BTU per hour.
Pressure
Pascals, bar, atmospheres, psi, mmHg, torr.
Data
Bits, bytes, kilobytes, megabytes, gigabytes, terabytes, and the binary kibi/mebi/gibi units.
Angle
Degrees, radians, gradians, arcminutes, arcseconds, turns.
Frequency
Hertz, kilohertz, megahertz, gigahertz, rpm.
Fuel economy
Litres per 100 km, km per litre, miles per US gallon, miles per UK gallon.
About this converter
Conversions use exact definitions where they exist (an inch is 25.4 mm, a pound is 0.45359237 kg, a US gallon is 3.785411784 L) and standard values elsewhere; results are shown to six significant figures. Temperature converts through Celsius; fuel economy is an inverse relation, so it converts through litres per 100 km. Everything runs in your browser and nothing you type is stored — the address bar simply keeps the value and units so you can bookmark or share a conversion. More tools: Tools for students, including the scientific calculator, which also understands units inline (5 km / 20 minutes to km/h).