Conversion Calculators
Units, temperature, number bases, and Roman numerals converted instantly.
8 calculators
- Unit ConverterConvert length, weight, area, volume, speed, time, data, energy, and pressure between every common metric and imperial unit, with exact factors.
- Temperature ConverterConvert between Celsius, Fahrenheit, Kelvin, and Rankine instantly, with the conversion worked step by step and a reference table of key temperatures.
- Roman Numeral ConverterConvert numbers to Roman numerals and Roman numerals back to numbers, with the subtractive rules explained and each symbol broken down.
- Number Base ConverterConvert numbers between binary, octal, decimal, hexadecimal, and any base from 2 to 36, with the repeated-division working shown step by step.
- Download Time CalculatorEstimate how long a download or upload takes from the file size and your connection speed, accounting for the bits-versus-bytes gap.
- Pressure ConverterConvert pressure between psi, bar, kilopascals, atmospheres, mmHg, and inHg — the units used in tyres, weather, diving, and engineering.
- Energy ConverterConvert energy between joules, kilojoules, calories, food Calories, watt-hours, kilowatt-hours, BTU, foot-pounds, and electronvolts.
- Speed ConverterConvert speed between mph, km/h, m/s, ft/s, knots, and Mach — the units of driving, running, sailing, aviation, and physics.