Specific Energy (Heating Value per Mass) Converter
Convert between 8 specific energy units instantly. Enter a value, pick your units and get the result with the formula, a full conversion table and worked examples.
1,000 BTU/lb in all specific energy units
Updates live as you type. Click a row to set it as the target unit.
| Unit | Symbol | Value |
|---|---|---|
| Joule per kilogram | J/kg | 2,326,000 |
| Kilojoule per kilogram | kJ/kg | 2,326 |
| Megajoule per kilogram | MJ/kg | 2.326 |
| Calorie per gram | cal/g | 555.556 |
| Kilocalorie per kilogram | kcal/kg | 555.556 |
| BTU per pound | BTU/lb | 1,000 |
| Watt hour per kilogram | Wh/kg | 646.111 |
| Kilowatt hour per kilogram | kWh/kg | 0.646111 |
How to Convert Specific Energy Units
Specific energy is energy per unit mass, used for fuel heating values and enthalpy. The SI unit is joule per kilogram (J/kg); fuel data is often listed in MJ/kg, kcal/kg or BTU/lb.
Every unit on this page is stored as a fixed factor relative to one reference unit, the joule per kilogram (J/kg). Converting is a two step multiply and divide:
- Multiply your value by the factor of the source unit to get the value in J/kg.
- Divide that result by the factor of the target unit.
BTU per pound to Kilojoule per kilogram conversion table
| BTU per pound (BTU/lb) | Kilojoule per kilogram (kJ/kg) |
|---|---|
| 1 BTU/lb | 2.326 kJ/kg |
| 2 BTU/lb | 4.652 kJ/kg |
| 3 BTU/lb | 6.978 kJ/kg |
| 4 BTU/lb | 9.304 kJ/kg |
| 5 BTU/lb | 11.63 kJ/kg |
| 6 BTU/lb | 13.956 kJ/kg |
| 7 BTU/lb | 16.282 kJ/kg |
| 8 BTU/lb | 18.608 kJ/kg |
| 9 BTU/lb | 20.934 kJ/kg |
| 10 BTU/lb | 23.26 kJ/kg |
| 15 BTU/lb | 34.89 kJ/kg |
| 20 BTU/lb | 46.52 kJ/kg |
| 25 BTU/lb | 58.15 kJ/kg |
| 30 BTU/lb | 69.78 kJ/kg |
| 40 BTU/lb | 93.04 kJ/kg |
| 50 BTU/lb | 116.3 kJ/kg |
| 75 BTU/lb | 174.45 kJ/kg |
| 100 BTU/lb | 232.6 kJ/kg |
| 250 BTU/lb | 581.5 kJ/kg |
| 500 BTU/lb | 1,163 kJ/kg |
| 1,000 BTU/lb | 2,326 kJ/kg |
Specific Energy Units and Conversion Factors
Value of one unit expressed in J/kg.
| Unit | Symbol | In J/kg |
|---|---|---|
| Joule per kilogram | J/kg | 1 |
| Kilojoule per kilogram | kJ/kg | 1,000 |
| Megajoule per kilogram | MJ/kg | 1,000,000 |
| Calorie per gram | cal/g | 4,186.8 |
| Kilocalorie per kilogram | kcal/kg | 4,186.8 |
| BTU per pound | BTU/lb | 2,326 |
| Watt hour per kilogram | Wh/kg | 3,600 |
| Kilowatt hour per kilogram | kWh/kg | 3,600,000 |
Frequently Asked Questions
What is the SI unit of specific energy?
The SI unit of specific energy is the joule per kilogram (J/kg). Specific energy is energy per unit mass, used for fuel heating values and enthalpy.
How do I convert BTU/lb to kJ/kg?
To convert btu per pound (BTU/lb) to kilojoule per kilogram (kJ/kg), multiply the value in BTU/lb by 2.326. For example, 1 BTU/lb = 2.326 kJ/kg.
How do I convert kJ/kg to BTU/lb?
To convert kilojoule per kilogram (kJ/kg) to btu per pound (BTU/lb), multiply the value in kJ/kg by 0.429923. For example, 1 kJ/kg = 0.429923 BTU/lb.
How do I convert kcal/kg to kJ/kg?
To convert kilocalorie per kilogram (kcal/kg) to kilojoule per kilogram (kJ/kg), multiply the value in kcal/kg by 4.1868. For example, 1 kcal/kg = 4.1868 kJ/kg.
Can I see a value in every specific energy unit at once?
Yes. Enter a value and choose the source unit; the "all units" table below the converter instantly lists the equivalent in all 8 supported units. Click any row to make it the target unit.
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