Unit Converter
Convert between common units across length, weight, temperature, volume, speed, and area in one place.
A single converter that handles all common unit categories without switching tabs or sites. I use the temperature and volume conversions most often in cooking contexts, and the length and area conversions for home improvement projects. Having all of them in one place with a consistent interface is the point.
Temperature conversion is the one that trips people most often. To convert Celsius to Fahrenheit: multiply by 9/5 then add 32. To convert Fahrenheit to Celsius: subtract 32, then multiply by 5/9. At -40, both scales are equal — that is the only crossover point.
Common conversions worth memorizing
Length: 1 inch = 2.54 cm. 1 mile = 1.609 km. 1 foot = 30.48 cm. Weight: 1 lb = 453.6 g. 1 kg = 2.205 lbs. 1 oz = 28.35 g. Volume: 1 gallon = 3.785 L. 1 cup = 237 mL. 1 fl oz = 29.57 mL. Speed: 1 mph = 1.609 km/h. 1 knot = 1.151 mph. Temperature: 100°C = 212°F (boiling). 0°C = 32°F (freezing). 37°C = 98.6°F (body temperature).
Frequently asked questions
Why does the UK use different units than the US?
Both countries inherited Imperial measurements from Britain, but the US customary system and Imperial system diverged when the UK metricated most units in the 1960s-70s. The UK still uses miles for road distances and pints for beer, but uses metric for most other purposes. US customary and Imperial units are similar but not identical — the US and Imperial gallon are different sizes (US gallon = 3.785 L, Imperial gallon = 4.546 L).