Converters
Every unit, every pair — length, weight, volume, temperature, data and more.
Number base converter Binary, octal, decimal, hex and any base from 2 to 36, with bit toggles. Roman numeral converter Numbers to Roman numerals and back, up to 3,999,999. Number to words Write out numbers in English — for cheques, contracts and homework. Length converter Distance and length, from nanometres to light-years. Weight & mass converter Grams, pounds, ounces, stones and tonnes. Volume converter Litres, gallons, cups, tablespoons and teaspoons — with the US/UK differences handled explicitly. Temperature converter Celsius, Fahrenheit, Kelvin and Rankine. Area converter Square metres, square feet, acres and hectares. Speed converter mph, km/h, knots, and the speed of sound. Time converter Seconds through centuries. Digital storage converter Bytes, kilobytes and kibibytes — the decimal/binary difference, made explicit. Data transfer rate converter Mbps, MB/s and the 8× confusion between them. Pressure converter PSI, bar, pascals and atmospheres — including tyre pressure. Energy converter Joules, calories, kilowatt-hours and BTU. Power converter Watts, horsepower and BTU per hour. Angle converter Degrees, radians, gradians and turns. Frequency converter Hertz through gigahertz, plus RPM. Fuel economy converter MPG and litres per 100 km. Note that L/100 km is inverse — lower is better. Density converter Grams per millilitre, pounds per cubic foot and friends. Force converter Newtons, pounds-force and kilograms-force. Tablespoons to teaspoons Convert tablespoons to teaspoons, with the formula and a quick reference table. Teaspoons to tablespoons Convert teaspoons to tablespoons, with the formula and a quick reference table. Cups to milliliters Convert cups to milliliters, with the formula and a quick reference table. Milliliters to cups Convert milliliters to cups, with the formula and a quick reference table. Cups to tablespoons Convert cups to tablespoons, with the formula and a quick reference table. Tablespoons to cups Convert tablespoons to cups, with the formula and a quick reference table. Fluid ounces to milliliters Convert fluid ounces to milliliters, with the formula and a quick reference table. Milliliters to fluid ounces Convert milliliters to fluid ounces, with the formula and a quick reference table. Liters to gallons Convert liters to gallons, with the formula and a quick reference table. Gallons to liters Convert gallons to liters, with the formula and a quick reference table. Pints to milliliters Convert pints to milliliters, with the formula and a quick reference table. Quarts to liters Convert quarts to liters, with the formula and a quick reference table. Sticks of butter to grams Convert sticks of butter to grams, with the formula and a quick reference table. Degrees Celsius to degrees Fahrenheit Convert degrees Celsius to degrees Fahrenheit, with the formula and a quick reference table. Degrees Fahrenheit to degrees Celsius Convert degrees Fahrenheit to degrees Celsius, with the formula and a quick reference table. Degrees Celsius to kelvin Convert degrees Celsius to kelvin, with the formula and a quick reference table. Kelvin to degrees Celsius Convert kelvin to degrees Celsius, with the formula and a quick reference table. Inchs to centimeters Convert inchs to centimeters, with the formula and a quick reference table. Centimeters to inchs Convert centimeters to inchs, with the formula and a quick reference table. Feet to meters Convert feet to meters, with the formula and a quick reference table. Meters to feet Convert meters to feet, with the formula and a quick reference table. Miles to kilometers Convert miles to kilometers, with the formula and a quick reference table. Kilometers to miles Convert kilometers to miles, with the formula and a quick reference table. Yards to meters Convert yards to meters, with the formula and a quick reference table. Meters to yards Convert meters to yards, with the formula and a quick reference table. Millimeters to inchs Convert millimeters to inchs, with the formula and a quick reference table. Inchs to millimeters Convert inchs to millimeters, with the formula and a quick reference table. Nautical miles to kilometers Convert nautical miles to kilometers, with the formula and a quick reference table. Light-years to kilometers Convert light-years to kilometers, with the formula and a quick reference table. Kilograms to pounds Convert kilograms to pounds, with the formula and a quick reference table. Pounds to kilograms Convert pounds to kilograms, with the formula and a quick reference table. Grams to ounces Convert grams to ounces, with the formula and a quick reference table. Ounces to grams Convert ounces to grams, with the formula and a quick reference table. Stone to pounds Convert stone to pounds, with the formula and a quick reference table. Stone to kilograms Convert stone to kilograms, with the formula and a quick reference table. Pounds to ounces Convert pounds to ounces, with the formula and a quick reference table. Tonnes to pounds Convert tonnes to pounds, with the formula and a quick reference table. Mile per hours to kilometer per hours Convert mile per hours to kilometer per hours, with the formula and a quick reference table. Kilometer per hours to mile per hours Convert kilometer per hours to mile per hours, with the formula and a quick reference table. Knots to mile per hours Convert knots to mile per hours, with the formula and a quick reference table. Meter per seconds to mile per hours Convert meter per seconds to mile per hours, with the formula and a quick reference table. Square feet to square meters Convert square feet to square meters, with the formula and a quick reference table. Square meters to square feet Convert square meters to square feet, with the formula and a quick reference table. Acres to square feet Convert acres to square feet, with the formula and a quick reference table. Acres to hectares Convert acres to hectares, with the formula and a quick reference table. Hectares to acres Convert hectares to acres, with the formula and a quick reference table. Megabytes to gigabytes Convert megabytes to gigabytes, with the formula and a quick reference table. Gigabytes to megabytes Convert gigabytes to megabytes, with the formula and a quick reference table. Gigabytes to terabytes Convert gigabytes to terabytes, with the formula and a quick reference table. Bytes to kilobytes Convert bytes to kilobytes, with the formula and a quick reference table. Mebibytes to megabytes Convert mebibytes to megabytes, with the formula and a quick reference table. Megabit per seconds to megabyte per seconds Convert megabit per seconds to megabyte per seconds, with the formula and a quick reference table. Pound per square inchs to bars Convert pound per square inchs to bars, with the formula and a quick reference table. Bars to pound per square inchs Convert bars to pound per square inchs, with the formula and a quick reference table. Pound per square inchs to kilopascals Convert pound per square inchs to kilopascals, with the formula and a quick reference table. Atmospheres to pound per square inchs Convert atmospheres to pound per square inchs, with the formula and a quick reference table. Kilocalories to kilojoules Convert kilocalories to kilojoules, with the formula and a quick reference table. Kilojoules to kilocalories Convert kilojoules to kilocalories, with the formula and a quick reference table. Kilowatt-hours to joules Convert kilowatt-hours to joules, with the formula and a quick reference table. British thermal units to kilowatt-hours Convert British thermal units to kilowatt-hours, with the formula and a quick reference table. Mechanical horsepowers to kilowatts Convert mechanical horsepowers to kilowatts, with the formula and a quick reference table. Kilowatts to mechanical horsepowers Convert kilowatts to mechanical horsepowers, with the formula and a quick reference table. Radians to degrees Convert radians to degrees, with the formula and a quick reference table. Degrees to radians Convert degrees to radians, with the formula and a quick reference table. Mile per US gallons to liters per 100 km Convert mile per US gallons to liters per 100 km, with the formula and a quick reference table. Liters per 100 km to mile per US gallons Convert liters per 100 km to mile per US gallons, with the formula and a quick reference table. Hours to minutes Convert hours to minutes, with the formula and a quick reference table. Days to hours Convert days to hours, with the formula and a quick reference table. Weeks to days Convert weeks to days, with the formula and a quick reference table. Years to days Convert years to days, with the formula and a quick reference table. Minutes to seconds Convert minutes to seconds, with the formula and a quick reference table.