Energy Converter
Convert energy between joules, calories, kilocalories, kilowatt-hours, BTU, therms and electronvolts.
Change the values and press Calculate to work out your own figures.
Enter an amount of energy, choose its unit and the unit you want. The answer is exact until it is shown, and the same value appears in every other unit.
Show the working
- 1 kWh = 3412.14163313 Btu
- 1 × 3412.14163313 = 3412.14163313 Btu
How to use it
Type an amount of energy, choose the unit it is in and the unit you want, then press Calculate. You can type decimals, fractions such as 3/8, mixed numbers such as 1 1/2, very large or small numbers such as 2.5e6, and simple sums such as 2*3. Swap exchanges the two units.
The answer is worked out with exact fractions and only rounded for display, to 12 significant figures. Below it you get the same value in every other unit on the list, and Show the working gives the factor that was used.
Key definitions
1 kWh = 3,600,000 J = 3.6 MJ 1 kcal = 4,184 J 1 BTU = 1,055.05585262 J 1 therm = 100,000 BTU
Calories and kilocalories
The 'Calories' on food labels are kilocalories: a 200 Calorie snack holds 200 kcal, or about 837 kJ. This converter uses the thermochemical calorie (4.184 J), the one US labelling uses.
Electricity and gas bills
Electricity is sold by the kilowatt-hour and natural gas often by the therm (100,000 BTU). One therm is about 29.3 kWh, which lets you compare heating costs.
Questions
How many BTU are in a kilowatt-hour?
About 3,412.14.
How many joules are in a food Calorie?
4,184: a food Calorie is a kilocalorie.
Formulas
result = (value × f(from) + o(from) − o(to)) ÷ f(to)
Sources
Limitations
- Only the units listed are supported here; other energy units arrive with later M4 slices.