Energy Converter
Enter a value and select units to convert
Enter a value and select units to convert
The energy converter allows you to convert between different units of energy, from SI units like joules to thermal units like BTUs and calories. This tool is useful for physics, engineering, thermodynamics, and many fields where energy measurements are needed. Energy is the capacity to do work or produce heat.
Common Energy Measurement Systems
SI and Metric System
The International System of Units (SI) uses the joule (J) as the standard unit of energy.
- Joule (J): The work done by a force of one newton over a distance of one meter
- SI prefixes can be used to create multiples: kJ, MJ, GJ, etc.
Thermal Energy Units
Units traditionally used for heat energy.
- Calorie (cal): The energy needed to raise the temperature of 1 gram of water by 1°C
- Kilocalorie (kcal): 1,000 calories, often used in nutrition (food calories)
- British Thermal Unit (BTU): The energy needed to raise the temperature of 1 pound of water by 1°F
- Therm: A large unit of heat energy, approximately 100,000 BTU
Electrical Energy Units
Units commonly used in electrical engineering and power generation.
- Watt-hour (Wh): Energy expended by a power of one watt over one hour
- Kilowatt-hour (kWh): Common unit for electricity billing
- Megawatt-hour (MWh) and Gigawatt-hour (GWh): Used for larger scale power production
Mechanical and Torque Units
Units based on force and distance.
- Foot-pound (ft·lbf): The energy needed to move one pound a distance of one foot
- Gram-force meter (gf·m) and Kilogram-force meter (kgf·m): Metric equivalents
Atomic and Nuclear Units
Units used at the atomic and subatomic levels.
- Electron volt (eV): Energy gained by an electron moving across an electric potential of one volt
- Hartree (Ha) and Rydberg (Ry): Units used in atomic and molecular physics
Other Units
Various specialized or historical units of energy.
- Erg: A CGS unit, equal to 10⁻⁷ joules
- Ton of TNT (tTNT): A unit of energy equal to the energy released in the detonation of one ton of TNT
- Horsepower-hour (hp·h): Energy delivered by one horsepower over one hour
Common Energy Conversions
| From | To | Multiply By |
|---|---|---|
| Joule | Calorie | 0.239006 |
| Joule | BTU | 0.000947817 |
| Joule | Kilowatt-hour | 2.77778 × 10⁻⁷ |
| Calorie | Joule | 4.184 |
| Kilocalorie | Joule | 4,184 |
| BTU | Joule | 1,055.06 |
| Kilowatt-hour | Joule | 3,600,000 |
| Electron volt | Joule | 1.602176634 × 10⁻¹⁹ |
| Foot-pound | Joule | 1.35582 |