Convert any unit, precisely.
A calm, accurate converter hub for length, weight, temperature, volume, speed, data and more. Pick a measurement, enter a value, and get the answer instantly. Everything runs in your browser.
Measurement categories
Distance and length
Weight and mass
Temperature scales
Volume and capacity
Surface area
Speed and velocity
Time and duration
Data and storage
Pressure and stress
Energy and work
Power output
Font sizes for screen and print
Popular conversions
Decimal amounts, worked out
Most converters only chart whole numbers, so the awkward amounts are the ones you end up doing by hand. These pages carry a full decimal table (0.38 lb, 0.02 m, 0.5 acre and the rest), the reverse direction, where the factor actually comes from, and the unit mix-ups worth knowing about.
The conversions people get wrong
Some pairs hide a genuine ambiguity, and the number a converter gives you is only half the answer. These pages explain the trap, with the exact factors and the sources they come from.
Why does my speedometer read faster than my GPS?
Why is one square metre 10,000 cm² and not 100?
Is 1 GB 1000 MB or 1024 MB?
Are the Calories on a food label kcal or cal?
Is a knot the same as a kilometre per hour?
How do you write grams as pounds and ounces?
Is 1 mL the same as 1 cc?
Why does 4.184 not match the kcal printed on the label?