Free Unit Converters

Length Converter

Convert between millimetres, centimetres, metres, kilometres, inches, feet, yards and miles.

Weight Converter

Convert between milligrams, grams, kilograms, tonnes, ounces, pounds and stone.

Temperature Converter

Convert between Celsius, Fahrenheit, Kelvin and Rankine.

Volume Converter

Convert between millilitres, litres, cubic metres, teaspoons, cups, pints and gallons.

Area Converter

Convert between square metres, hectares, acres, square feet and square miles.

Speed Converter

Convert between kilometres per hour, miles per hour, metres per second, knots and Mach.

Data Size Converter

Convert bytes, KB, MB, GB and TB, decimal or binary, see what a drive shows in Windows or macOS, time a transfer, and get Excel and ls formulas.

Pressure Converter

Convert between bar, psi, kPa, atmospheres, mmHg, inHg and torr — for tyres, weather, diving and engineering.

Energy Unit Converter

Convert joules, calories, kcal, kWh, BTU, therms, toe and eV with the working shown, plus kJ/mol and kT, power × time, E = mc² and METs.

Power Unit Converter

Convert between watts, kilowatts, horsepower, metric horsepower (PS) and BTU per hour.

Time Zone Converter

Convert a date and time between time zones, with daylight saving handled by your browser's own time-zone data.

Watts, Amps and Volts Calculator

Work out watts, amps or volts from the other two for DC, single-phase AC or three-phase AC circuits.

Blood Glucose Converter

Convert blood glucose between mg/dL, mmol/L and g/L, HbA1c between % and mmol/mol, and A1c to and from average glucose (eAG, GMI).

Shoe Size Converter

Convert shoe sizes between US men's, US women's, UK, EU and foot length in cm, for adults and kids.

Latitude and Longitude Converter

Convert coordinates between decimal degrees, DMS, DDM, UTM, MGRS, UK grid references and Web Mercator x/y, one at a time or as a list.

Pixels to Inches Converter

Convert between pixels, inches, cm and mm at any DPI, and find the pixels needed for a print size.

Currency Converter

Convert 165 currencies at the daily mid-market rate or on any date since 1999, with a rate chart, a markup check and the central banks behind each rate.

Cooking Converter

Grams to cups for 27 ingredients, dry to cooked rice and pasta, raw to cooked meat, slow cooker, Instant Pot and air fryer times, and oven temperatures.