3 converters · 19 units
Energy & Power
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.
Energy
8 units
0.001
1 J = 0.001 kJ
Power
7 units
0.001
1 W = 0.001 kW
Fuel Consumption
4 units
100
1 km/L = 100 L/100km
The same energy, quoted by different trades
Joules come from physics, calories from food labels, BTU from heating and cooling, kilowatt-hours from the electricity bill. They describe one quantity, and this family moves between them directly rather than through a chain of intermediate steps.
Power lines up a motor rated in kilowatts against one rated in horsepower. Fuel consumption turns litres per hundred kilometres into miles per gallon and back, which is the only honest way to compare vehicles sold in different markets.