Unit Converters
Convert measurements for everyday tasks, cooking, cars, computing and energy using one accurate unit conversion engine.
Everyday measurements
Unit Converter
Free unit converter for 20+ categories including length, weight, temperature, volume, data storage, internet speed, pressure, energy, power, fuel economy and electrical units.
Length Converter
Free length converter for metres, centimetres, feet, inches, yards, miles, kilometres and nautical miles. Exact factors and instant results.
Weight Converter
Free weight converter for kilograms, grams, pounds, ounces, stone and tonnes. Exact factors for kg to lb, lb to kg and stone to kg conversions.
Temperature Converter
Free temperature converter for Celsius, Fahrenheit and Kelvin. See the formulas, oven temperatures and body temperature conversions instantly.
Volume Converter
Free volume converter for litres, millilitres, US and UK gallons, cups, pints, quarts, fluid ounces, tablespoons, teaspoons and cubic metres.
Area Converter
Free area converter for square metres, square feet, acres, hectares, square kilometres, square miles, square yards and square inches. Exact results.
Speed Converter
Free speed converter for kilometres per hour, miles per hour, knots, metres per second and feet per second. Exact results for driving and sailing.
Time Converter
Free time converter for milliseconds, seconds, minutes, hours, days, weeks and years. Convert hours to minutes, days to hours and more instantly.
Fuel Economy Converter
Free fuel economy converter for litres per 100 km, kilometres per litre, US MPG and UK (imperial) MPG. Compare car fuel consumption worldwide.
Computing and data
Data Storage Converter
Free data storage converter for bits, bytes, KB, MB, GB, TB, PB and binary KiB, MiB, GiB and TiB. See why a 1 TB drive shows 931 GB.
Storage Calculator
Calculate how much storage a collection of files uses and how much capacity remains. Supports decimal GB and binary GiB units.
Download Time Calculator
Estimate download time from file size and internet speed. Convert GB, GiB and Mbps to a clear time estimate in seconds, minutes and hours.
Science and engineering
Pressure Converter
Free pressure converter for bar, psi, pascal, kilopascal, megapascal, millibar, atmospheres and torr. Ideal for tyre, weather and hydraulic pressure.
Energy Converter
Free energy converter for joules, kilojoules, megajoules, watt-hours, kilowatt-hours, calories, kilocalories and BTU. Exact factors, instant results.
Power Converter
Free power converter for watts, kilowatts, megawatts, mechanical horsepower, metric horsepower (PS) and BTU per hour. Exact, instant results.
Frequency Converter
Free frequency converter for hertz, kilohertz, megahertz, gigahertz, terahertz and revolutions per minute (RPM). Instant and exact results.
Angle Converter
Free angle converter for degrees, radians, gradians, arcminutes and arcseconds. Convert degrees to radians and back with the exact formula.
Force Converter
Free force converter for newtons, kilonewtons, pound-force, kilogram-force and dynes. Convert N to lbf, kgf to N and more with exact definitions.
Torque Converter
Free torque converter for newton-metres, kilonewton-metres, pound-feet and pound-inches. Convert engine torque and torque wrench settings exactly.
Density Converter
Free density converter for kilograms per cubic metre, grams per cubic centimetre, grams per millilitre, pounds per cubic foot and pounds per US gallon.
Acceleration Converter
Free acceleration converter for metres per second squared, standard gravity (g) and feet per second squared. Convert g-force to m/s² and back.
Illuminance Converter
Free illuminance converter for lux, kilolux, foot-candles and phot. Convert lux to foot-candles for lighting design, photography and plant grow lights.
Electrical Units Converter
Free electrical units converter for volts, millivolts, kilovolts, amps, milliamps, ohms, kilohms, megohms, watts and kilowatts. Includes Ohm’s law.
Popular presets
- Bar to PSI
- Kilowatt-hours to Joules
- Kilowatts to Horsepower
- Radians to Degrees
- Newtons to Pounds-force
- Newton-metres to Pound-feet
- Litres per 100 km to US MPG
- g/cm³ to lb/ft³
- Standard Gravity to m/s²
- Lux to Foot-candles
- Mbps to MB/s
- Volts to Millivolts
- Amps to Milliamps
- Ohms to Kilohms
- Grams to Cups by Ingredient
- Centimetres to Inches
- Inches to Centimetres
- Kilograms to Pounds
- Pounds to Kilograms
- Celsius to Fahrenheit
- Fahrenheit to Celsius
- Kilometres to Miles
- Miles to Kilometres
- MB to GB
- GB to MB
- KB to MB
- GB to TB
- Mbit to MB (Megabits to Megabytes)
- MHz to GHz
- GHz to MHz
Unit converters for measurements and everyday questions
Choose a measurement category, enter a value and select its source and target units. The converters cover metric and customary measurements, from metres, kilograms and litres to miles, pounds and US or UK gallons. Temperature uses the Celsius, Fahrenheit and Kelvin scales; fuel economy accounts for the difference between US and UK gallons.
Measurements
Convert length, weight, temperature, volume, area, speed, time, pressure, angle, force, torque, density, acceleration and illuminance. Unit factors are based on standard definitions; temperature and fuel economy use their dedicated conversion formulas.
Cooking and automotive
Use volume conversions for cups, tablespoons, teaspoons and millilitres, and temperature conversions for Celsius and Fahrenheit oven settings. Convert road speed, torque, engine power and fuel economy between common metric and US or UK units. Cup-to-gram conversions depend on the ingredient’s density, so use a recipe-specific weight when precision matters.
Computing and energy
Convert bytes and bits using decimal (KB, MB, GB) or binary (KiB, MiB, GiB) definitions. Internet transfer rates distinguish bits per second from bytes per second: 100 Mbps is 12.5 MB/s before network overhead. Estimate download duration from file size and connection speed, or compare used and available storage. Convert joules, kilowatt-hours, calories and BTU, and compare watts, kilowatts and horsepower. The electricity cost calculator is in Home & DIY.
Decimal and binary storage units
Storage manufacturers use powers of 1,000: 1 GB is 1,000,000,000 bytes. Binary units use powers of 1,024: 1 GiB is 1,073,741,824 bytes. This explains why a drive’s advertised capacity can look lower when an operating system reports a binary amount with decimal labels.
How long does a download take?
Divide the file size in bits by the connection rate in bits per second. For example, 100 GB at 100 Mbps takes about 2 hours and 13 minutes under ideal conditions. Actual downloads can take longer because of network overhead, Wi-Fi quality, server limits and other traffic.