Energy Converter

Energy Converter – Joule, Calorie, Btu, kWh, eV

Easily convert between all major energy units (joule, kilojoule, kilowatt-hour, calorie, Btu, electron-volt, erg, foot-pound, newton-meter) with this free online tool. Enter your value, select units, and get instant, accurate results with calculation steps and a handy conversion table.

How to Convert Energy Units

To convert from one energy unit to another, first convert to joules, then to the target unit.
value_in_target = value_in_source × (source_to_joules / target_to_joules)

Examples

• 1 kilowatt-hour = 3.6 million joules = 860.42 kilocalories
• 1 calorie = 4.184 joules
• 1 Btu (IT) = 1055.06 joules = 252.16 calories
• 1 electron-volt = 1.602 × 10⁻¹⁹ joules
• 1 foot-pound = 1.35582 joules

Common Energy Units

Joule (J), kilojoule (kJ), kilowatt-hour (kWh), calorie (cal), kilocalorie (kcal), Btu (IT), electron-volt (eV), erg, foot-pound (ft·lbf), and newton-meter (N·m) are the most common energy units used in physics, engineering, and daily life.