Energy converter

Joules, calories, kWh, BTU.

Worked example

1 kWh = 3600000 J. Type into either side of the converter above and the other side updates as you type — no Convert button, no page reload.

Kilowatt-hour to Joule conversion table

Quick reference at the most common values. For any other input, use the live converter above.

Common energy conversions

Pick a different unit pair from the dropdowns above to see any of these.

• joules ↔ calories
• kWh ↔ joules
• BTU ↔ joules
• kcal ↔ kJ

About energy units

Energy unifies thermodynamics, electricity, and food. The joule is the SI base; calories matter for nutrition (the Calorie on a food label is technically a kilocalorie); kilowatt-hours show up on every electricity bill; BTU dominates HVAC specs in the US. They all measure the same quantity in different clothes.

Privacy

Every conversion above runs as a small JavaScript function in your browser. The values you type are never sent to a server — see the Privacy Policy for the full breakdown of what stays on your device and what (very little) we log.

Browse all unit categories · read about the project