Energy Converter
Convert joules, kWh, calories, kilocalories, and BTU without confusing energy with power.
Result
Enter a value to convert.
The calculation runs locally in your browser.
What this tool converts
Convert electrical, thermal, and mechanical energy across J, kJ, Wh, kWh, cal, kcal, and BTU.
How the conversion works
Enter a value, choose source and target units, and the result updates immediately. Dynamic equivalents use the same engine and internal precision.
Target energy = Source energy in joules ÷ joules per target unit
Verifiable example
1 kWh equals 3,600,000 J. One kcal equals 1,000 small calories and 4,184 J.
Calculations run locally in the browser and require no external API.
Frequently asked questions
How many joules are in a kWh?
One kWh is exactly 3,600,000 J.
Are calorie and kilocalorie the same?
No. 1 kcal equals 1,000 small calories.
Are energy and power the same?
No. Energy is an accumulated amount; power is the rate at which energy is used or transferred.