Unit Converter

Convert between units of length, weight, temperature, volume, and more.

How It Works

Select a measurement category (length, mass, temperature, volume, area, speed, etc.), enter the value, and choose source and target units. Convert instantly.

**Unit Converter — Convert Any Measurement Instantly**

From centimetres to inches to metres to feet, from kilograms to pounds to ounces, our Unit Converter handles all common unit conversions across every major measurement category.

**Measurement Categories**

**Length**
Millimetre, centimetre, metre, kilometre, inch, foot, yard, mile, nautical mile, light-year, parsec

**Mass / Weight**
Milligram, gram, kilogram, tonne, ounce, pound, stone, US ton, metric ton

**Temperature**
Celsius (°C), Fahrenheit (°F), Kelvin (K)
- °F = (°C × 9/5) + 32
- K = °C + 273.15

**Volume**
Millilitre, litre, cubic metre, teaspoon (US), tablespoon (US), fluid ounce, cup (US), pint, quart, gallon (US/UK)

**Area**
Mm², cm², m², km², in², ft², yd², acre, hectare, mi²

**Speed**
m/s, km/h, mph, knots, feet per second, Mach number

**Data Storage**
Bits, bytes, kilobytes, megabytes, gigabytes, terabytes, petabytes

**Time**
Milliseconds, seconds, minutes, hours, days, weeks, months, years

**Energy**
Joules, kilojoules, kilowatt-hours, calories, kilocalories, BTU

**Pressure**
Pascal, kilopascal, megapascal, bar, psi, atm, mmHg

**Common Conversion Factors to Know**

- 1 inch = 2.54 cm
- 1 kg = 2.20462 lbs
- 1 mile = 1.60934 km
- 1 litre = 0.264172 US gallons
- 1 acre = 0.404686 hectares
- 0°C = 32°F = 273.15K

**Why Unit Conversion Matters**

Science and engineering require precise unit conversions. NASA lost the Mars Climate Orbiter in 1999 due to a unit conversion error — one team used imperial units, another metric. Unit conversion errors have caused aircraft to run out of fuel mid-flight and bridges to be built at the wrong scale.

Frequently Asked Questions

°F = (°C × 9/5) + 32. Example: 25°C = (25 × 9/5) + 32 = 45 + 32 = 77°F.
1 pound = 0.453592 kg. So 1 kg = 2.20462 lbs.
Mass is the amount of matter (measured in kg). Weight is the force of gravity on that mass (measured in Newtons). On Earth, 1 kg has a weight of ~9.81 Newtons. In everyday use, the terms are used interchangeably.
Yes. The length converter includes astronomical units, light-years, and parsecs for science and astronomy applications.
1 US gallon = 3.785 litres. 1 UK (imperial) gallon = 4.546 litres. They are different — specify which you mean when converting.