Energy Converter

This free online Energy Converter allows you to instantly convert between different units of energy. Energy is the quantitative property that must be transferred to a body or physical system to perform work on the body, or to heat it. The standard SI unit is the Joule (J).

Supported Units

• Joule (J): The SI derived unit of energy.
• Kilojoule (kJ): 1,000 Joules.
• Megajoule (MJ): One million Joules.
• Erg: The CGS unit of energy. 1 erg = 10⁻⁷ J.
• Calorie (cal): The energy needed to raise the temperature of 1 gram of water by 1°C. 1 cal ≈ 4.184 J.
• Kilocalorie (kcal): 1,000 calories. Often called 'Calories' in food labeling.
• Watt-hour (Wh): The energy equivalent to one watt of power expended for one hour.
• Kilowatt-hour (kWh): 1,000 Watt-hours. Commonly used for electricity billing.
• Electron-volt (eV): The amount of kinetic energy gained by a single electron accelerating from rest through an electric potential difference of one volt.
• British Thermal Unit (BTU): The amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit.
• Therm (US): Approx. 100,000 BTU.
• Foot-pound (ft⋅lb): The energy transferred on applying a force of one pound-force through a displacement of one foot.