Unit converter
Convert between metric and imperial units. Pick a quantity, type a value and see it in every unit at once.
How it works
Every unit is stored as a factor to one base unit (metre, kilogram, litre, square metre, metre per second, byte). A value is multiplied by the factor of its unit and divided by the factor of the target. Temperature is the exception, because its scales have different zero points:
°F = °C × 9/5 + 32K = °C + 273.15Worked example
5 miles in kilometres:
- 1 mile = 1609.344 m
- 5 × 1609.344 = 8046.72 m
- 8046.72 ÷ 1000 = 8.04672 km
Frequently asked questions
How exact are the conversions?
They use the exact legal definitions where they exist (1 inch = 2.54 cm, 1 pound = 0.45359237 kg, 1 US gallon = 3.785411784 L) and are shown with up to 8 significant digits.
Are gallons and ounces US or imperial?
Both are listed: “US gallon” and “imperial gallon” differ by about 20%, and fluid ounces differ too, so pick the one your recipe or label uses.
Why is a megabyte sometimes 1000 and sometimes 1024 kilobytes?
Storage makers use decimal units (1 MB = 1,000,000 bytes); operating systems often count in binary units (1 MiB = 1,048,576 bytes). Both kinds are in the Data list.