Fuel Energy per Mass Converter
Convert fuel heating values and specific energy between MJ/kg, kJ/kg, J/kg, kWh/kg, Wh/kg, BTU/lb and kcal/kg.
Convert fuel energy per mass
Result
Fuel Energy per Mass units
Every unit below converts to every other one in the calculator. Values are relative to the base unit, the joule per kilogram (J/kg).
| Unit | Symbol | System | Value |
|---|---|---|---|
| Joule per kilogram | J/kg | SI | Base unit |
| Kilojoule per kilogram | kJ/kg | SI | = 1000 J/kg |
| Megajoule per kilogram | MJ/kg | SI | = 1000000 J/kg |
| Kilowatt-hour per kilogram | kWh/kg | SI-accepted | = 3600000 J/kg |
| Watt-hour per kilogram | Wh/kg | SI-accepted | = 3600 J/kg |
| BTU per pound | BTU/lb | US customary | = 2326 J/kg |
| Kilocalorie (IT) per kilogram | kcal/kg | metric | = 4186.8 J/kg |
Joule per kilogram quick reference
| Joule per kilogram | Kilojoule per kilogram | Megajoule per kilogram | Kilowatt-hour per kilogram |
|---|---|---|---|
| 1 J/kg | = 0.001 kJ/kg | = 0.000001 MJ/kg | ≈ 2.777777778e-7 kWh/kg |
| 10 J/kg | = 0.01 kJ/kg | = 0.00001 MJ/kg | ≈ 0.000002777777778 kWh/kg |
| 100 J/kg | = 0.1 kJ/kg | = 0.0001 MJ/kg | ≈ 0.00002777777778 kWh/kg |
| 1000 J/kg | = 1 kJ/kg | = 0.001 MJ/kg | ≈ 0.0002777777778 kWh/kg |
Among the 7 fuel energy per mass units on this page, the smallest is the joule per kilogram (J/kg) and the largest is the kilowatt-hour per kilogram (kWh/kg).
More fuel energy per mass conversions
- Megajoule per kilogram to BTU per poundMJ/kg → BTU/lb
- BTU per pound to Megajoule per kilogramBTU/lb → MJ/kg
- Kilojoule per kilogram to BTU per poundkJ/kg → BTU/lb
- BTU per pound to Kilojoule per kilogramBTU/lb → kJ/kg
- Kilowatt-hour per kilogram to Megajoule per kilogramkWh/kg → MJ/kg
- Megajoule per kilogram to Kilowatt-hour per kilogramMJ/kg → kWh/kg
About fuel energy per mass units
Energy per mass, or specific energy, is the energy contained in one unit of mass. For fuels it is the heating value (calorific value): the heat released by burning one kilogram. Its SI unit is the joule per kilogram (J/kg); fuels are usually stated in MJ/kg and batteries in Wh/kg.
One BTU/lb is exactly 2326 J/kg, one kcal/kg (IT) is exactly 4186.8 J/kg and one kWh/kg is exactly 3.6 MJ/kg. Heating values are given as higher (gross) or lower (net) values, which differ by the heat in the water vapor formed, so check which one a figure means before comparing.
Frequently asked questions
- How do I convert MJ/kg to BTU/lb?
- Multiply by about 429.923 (1,000,000 ÷ 2326). For example, 46 MJ/kg is about 19,776 BTU/lb.
- What is the difference between higher and lower heating value?
- The higher heating value (HHV, gross) includes the heat released when the water vapor from combustion condenses. The lower heating value (LHV, net) leaves it out, so for fuels that contain hydrogen it is the smaller number.
- How many Wh/kg are in 1 MJ/kg?
- About 277.78 Wh/kg. One Wh/kg is exactly 3.6 kJ/kg.
- How many kilojoules per kilogram are in one joule per kilogram?
- One joule per kilogram = 0.001 kJ/kg (kilojoules per kilogram).
- How many megajoules per kilogram are in one joule per kilogram?
- One joule per kilogram = 0.000001 MJ/kg (megajoules per kilogram).
- How many kilowatt-hours per kilogram are in one joule per kilogram?
- One joule per kilogram ≈ 2.777777778e-7 kWh/kg (kilowatt-hours per kilogram).