Energy Converter
Convert joules, kilojoules, calories, kcal, Wh, kWh, and BTU instantly — nothing is uploaded.
Result
Energy unit conversion
Enter a value and choose the input and output units to convert between joules (J), kilojoules (kJ), calories (cal), kilocalories (kcal), watt-hours (Wh), kilowatt-hours (kWh), and British Thermal Units (BTU). No upload, no signup — everything runs locally.
Base unit: joule (J). 1 cal = 4.184 J. 1 kcal = 4,184 J. 1 kWh = 3,600,000 J. 1 BTU ≈ 1,055.056 J.
FAQ
How many joules in a kilocalorie? 1 kcal = 4,184 J (the “food calorie” used in nutrition).
Is my data sent anywhere? No — all calculations happen in your browser.