7 converters · 56 units
Basic Unit Conversions
Put a figure in the left-hand box and read the answer on the right. Nothing is submitted anywhere — the maths runs where you are sitting.
Length
10 units
1 mm = 0.1 cm
Weight
8 units
1 mg = 0.001 g
Temperature
3 units
1 °C = 33.8 °F
Area
10 units
1 mm² = 0.01 cm²
Volume
11 units
1 mL = 0.001 L
Speed
6 units
1 m/s = 3.599999997 km/h
Time
8 units
1 ms = 0.001 s
Everyday measures, without the guesswork
The conversions people actually reach for are mundane ones: a recipe written in cups, a road sign in miles, a parcel limit in pounds, an oven dial in Fahrenheit. Each converter below keeps a whole family of units in a single list, so going from millimetres to feet takes one step rather than three.
Temperature is the one that trips people up, because Celsius, Fahrenheit and Kelvin do not share a zero point. We apply the full formula instead of a single ratio, which is why 0 °C comes back as 32 °F and −40 lands on −40 in both scales.