Fuel Efficiency (Mass) Converter
Convert between units of energy per unit mass (e.g., J/kg, BTU/lb) and mass per unit energy (e.g., kg/J, lb/BTU).
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Understanding Fuel Efficiency (Mass Basis)
Fuel efficiency on a mass basis refers to the amount of energy released per unit mass of fuel, or its reciprocal, the amount of mass required to release a unit of energy. Higher energy per mass (e.g., J/kg) indicates a more energy-dense fuel. Conversely, lower mass per energy (e.g., kg/J) also indicates better efficiency.
The SI unit for energy per mass is Joules per kilogram (J/kg).
| Unit Type | Unit Name | Symbol | Relation to J/kg (Approx.) |
|---|---|---|---|
| Energy/Mass | Joule/kilogram | J/kg | Base unit (1 J/kg) |
| Energy/Mass | Kilojoule/kilogram | kJ/kg | 1000 J/kg |
| Energy/Mass | Calorie (IT)/gram | cal(IT)/g | 4186.8 J/kg |
| Energy/Mass | BTU (IT)/pound | BTU(IT)/lb | 2326 J/kg |
| Mass/Energy | Kilogram/joule | kg/J | Reciprocal of J/kg |
| Mass/Energy | Gram/calorie (IT) | g/cal(IT) | Reciprocal of cal(IT)/g |