Energy Conversion Calculator

This energy converter switches between joules, calories, kilocalories, kilowatt-hours, and BTU.

Formula notes

1 kcal = 4184 J; 1 kWh = 3.6×10⁶ J = 860 kcal; 1 BTU ≈ 1055 J.

Worked examples

1. Example: 2000 kcal (a daily food budget) ≈ 8.37 MJ ≈ 2.32 kWh.
2. A 2 kWh appliance use equals 7.2 MJ because 1 kWh is exactly 3.6 MJ.

How to use it

1. Enter the energy amount and its unit.
2. Read the equivalent in the other units.
3. Use kWh for electricity bills and kcal for food.

Frequently asked questions

Limits and interpretation

• Energy and power are different quantities: kWh cannot be converted to kW without a time interval.
• Food calories usually mean kilocalories, so confirm whether a source labelled cal actually intends kcal.

References

• NIST: SI Units