Unit Converters
Straightforward conversions with exact factors — the international inch has been exactly 25.4 mm since 1959, and these tables use that rather than a rounded approximation. Where a conversion is not a simple multiplication, such as temperature or fuel economy, the calculator handles it properly instead of pretending it is.
- Length Converter
Convert between millimetres, centimetres, metres, kilometres, inches, feet, yards and miles.
- Weight and Mass Converter
Convert between grams, kilograms, tonnes, ounces, pounds, stone and US tons.
- Volume Converter
Convert between millilitres, litres, teaspoons, cups, pints, quarts, gallons and cubic units.
- Temperature Converter
Convert between Fahrenheit, Celsius and Kelvin, with all three shown at once.
- Cooking Measurement Converter
Convert cups, tablespoons and millilitres to grams and ounces, using the density of the actual ingredient.
- Area Converter
Convert between square feet, square metres, square yards, acres, hectares and square miles.
- Speed Converter
Convert between miles per hour, kilometres per hour, metres per second, feet per second and knots.
- Pressure Converter
Convert between psi, bar, pascals, kilopascals, atmospheres and mercury column units.
- Fuel Economy Converter
Convert between US mpg, imperial mpg, litres per 100 km and kilometres per litre.
- Data Storage Converter
Convert between bytes, kilobytes, megabytes, gigabytes and their binary equivalents.
- Time Duration Calculator
Add or subtract two durations in hours, minutes and seconds, with decimal hour totals.
- Oven Temperature Converter
Convert oven temperatures between Celsius, Fahrenheit and gas mark, with fan oven adjustments.
- Fraction and Decimal Converter
Convert a decimal to the nearest simple fraction, or a fraction to a decimal and percentage.
- Roman Numeral Converter
Convert numbers to Roman numerals and Roman numerals back to numbers, with a validity check.
- Metric Prefix Converter
Convert a value between metric prefixes, from pico through tera, for any SI unit.