Energy Converter — J, kJ, cal, kcal, BTU, Wh & kWh

Easiest Converter’s energy converter delivers fast, trustworthy results for science coursework, engineering, HVAC sizing, cooking/nutrition, and utility analyses. Convert between joule (J), kilojoule (kJ), calorie (cal), kilocalorie (kcal), British thermal unit (BTU), watt-hour (Wh), kilowatt-hour (kWh), and erg with clean, shareable output.

Calculations are referenced to the joule for consistent math across systems. Popular pairs include kJ ⇄ kcal for nutrition labels, Wh ⇄ kWh for appliances and bills, and BTU ⇄ kWh for heating and cooling equipment. For very small quantities, switch to cal or erg; for metering and tariffs, use kWh.

Why use this energy converter? The interface is tuned for clarity—keyboard-friendly inputs, a one-tap swap, and a copy-to-clipboard result string. Outputs use sensible precision so numbers stay readable while remaining accurate for reports, specs, and lab notes.

Supported units: J, kJ, cal, kcal, BTU, Wh, kWh, erg. Whether you’re comparing appliance usage, converting recipe energy, or translating datasheets, this tool keeps conversions quick, consistent, and easy to share.

• Use ⇄ to swap “From” and “To” instantly.
• Click 📋 to copy a neat result string for notes or emails.
• Use kWh for electricity costs, BTU for heating/cooling, and kcal for nutrition.