Unit Conversions calculators
Length, weight, temperature and other units
- Area Converter Square meters, feet, acres and hectares
- Energy Converter Joules, calories, kWh and BTU
- Fuel Economy Converter Convert MPG, L/100 km and km/L
- Length Converter Meters, feet, inches, miles and more
- Pressure Converter PSI, bar, kPa, atm and mmHg
- Shoe Size Converter US, UK and EU sizes plus foot length
- Speed Converter Convert km/h, mph, m/s and knots
- Temperature Converter Celsius, Fahrenheit and Kelvin in one step
- Volume Converter Liters, gallons, cups, pints and more
- Weight Converter Kilograms, pounds, stone, ounces and more
Which converter to use
Most converters take a value, the unit it is in and the unit you want. Units with an exact definition are stored exactly, so a foot is 0.3048 meters, not a rounded approximation of it. The length converter and the weight converter cover the metric and imperial units in daily use, and the temperature converter handles Celsius, Fahrenheit and Kelvin with exact formulas, because temperature scales differ by an offset as well as a factor.
Kitchen measures are a separate case. The volume converter covers liters, gallons, pints and cups, but turning a cup of flour into grams depends on the ingredient, which is what the cups to grams converter in the cooking section is for. Square meters, square feet, acres and hectares have their own area converter. The speed, pressure, energy and fuel economy converters handle km/h and mph, PSI and bar, joules and kilowatt-hours, and MPG against liters per 100 km.
Shoe sizes are the exception to exact conversion. The shoe size converter looks a size up in a retail chart for US, UK and EU sizes and shows the matching foot length, so treat its result as a guide to try on rather than a guarantee of fit.