Common Converters
Energy Converter
Convert between joules, calories, BTU, kilowatt-hours and foot-pounds. The joule is the SI unit of energy; the thermochemical calorie is defined as exactly 4.184 J.
ENERGY CONVERTER — INSTANT RESULT
All supported units — energy
| Unit | Symbol | To joule (J) | From joule (J) |
|---|---|---|---|
| Joule | J | 1 J = 1 J | 1 J = 1 J |
| Kilojoule | kJ | 1 kJ = 1,000 J | 1 J = 0.001 kJ |
| Megajoule | MJ | 1 MJ = 1,000,000 J | 1 J = 1e-06 MJ |
| Gigajoule | GJ | 1 GJ = 1,000,000,000 J | 1 J = 1e-09 GJ |
| Calorie | cal | 1 cal = 4.184 J | 1 J = 0.23900574 cal |
| Kilocalorie (food Calorie) | kcal | 1 kcal = 4,184 J | 1 J = 0.00023900574 kcal |
| Watt-hour | Wh | 1 Wh = 3,600 J | 1 J = 0.00027777778 Wh |
| Kilowatt-hour | kWh | 1 kWh = 3,600,000 J | 1 J = 2.7777778e-07 kWh |
| Megawatt-hour | MWh | 1 MWh = 3,600,000,000 J | 1 J = 2.77778e-10 MWh |
| BTU | BTU | 1 BTU = 1,055.05585262 J | 1 J = 0.00094781712 BTU |
| Therm (US) | thm | 1 thm = 105,480,400 J | 1 J = 9.48043e-09 thm |
| Quad | quad | 1 quad = 1.05506e+18 J | 1 J = 9.47817e-19 quad |
| Foot-pound | ft·lb | 1 ft·lb = 1.35581795 J | 1 J = 0.73756215 ft·lb |
| Inch-pound | in·lb | 1 in·lb = 0.11298483 J | 1 J = 8.85074579 in·lb |
| Electronvolt | eV | 1 eV = 1.60218e-19 J | 1 J = 6.24151e+18 eV |
| Erg | erg | 1 erg = 1e-07 J | 1 J = 10,000,000 erg |
| Horsepower-hour | hp·h | 1 hp·h = 2,684,519.537696 J | 1 J = 3.7250614e-07 hp·h |
| Ton of TNT | tTNT | 1 tTNT = 4,184,000,000 J | 1 J = 2.39006e-10 tTNT |
Popular energy conversions
kJ to kcalkcal to kJBTU to JkWh to JkWh to BTUJ to calcal to Jft·lb to JkWh to kcaleV to Jhp·h to kWhBTU to kWhWh to J
Frequently asked questions
What units does this energy converter support?
It supports 18 units: Joule (J), Kilojoule (kJ), Megajoule (MJ), Gigajoule (GJ), Calorie (cal), Kilocalorie (food Calorie) (kcal), Watt-hour (Wh), Kilowatt-hour (kWh), Megawatt-hour (MWh), BTU (BTU), Therm (US) (thm), Quad (quad), Foot-pound (ft·lb), Inch-pound (in·lb), Electronvolt (eV), Erg (erg), Horsepower-hour (hp·h), Ton of TNT (tTNT).
What is the base unit of energy?
The SI reference unit is the joule (J). Every conversion is computed by converting the input to the base unit, then from the base unit to the target unit, so chained precision is preserved.
Is this converter accurate?
Yes. Conversion factors use exact legal definitions where they exist (for example 1 in = 25.4 mm exactly) and CODATA/ISO constants otherwise. Results are shown to up to 10 significant figures.