What this converter does
This converter changes calorific (heating) value from MJ/kg to BTU/lb and back, plus kcal/kg and kJ/kg. Fuel energy content is quoted differently across regions, so a fixed-factor conversion keeps values consistent. Type a value and read the answer instantly.
One MJ/kg equals about 429.9 BTU/lb, so a 45 MJ/kg diesel is roughly 19,300 BTU/lb.
The units it covers
Specific-energy (heating-value) units, each expressed against MJ/kg.
View all units & their values
| Unit | Symbol | Value | Mainly used |
|---|---|---|---|
| Megajoule per kilogram | MJ/kg | 1 | SI heating value |
| Kilocalorie per kilogram | kcal/kg | 0.004184 | Metric fuel tables |
| BTU per pound | BTU/lb | 0.002326 | US fuel tables |
| Kilojoule per kilogram | kJ/kg | 0.001 | SI, smaller values |
The formula
Each unit has a fixed value in MJ/kg, so any pair converts through it:
result = value × factor_from ÷ factor_toWhere:
- value = the number you typed
- factor_from = the “from” unit in MJ/kg
- factor_to = the “to” unit in MJ/kg
Worked example
Convert 45 MJ/kg to BTU/lb.
1 MJ/kg = 429.923 BTU/lb45 × 429.923 = 19,347 BTU/lbSo diesel at 45 MJ/kg has about 19,347 BTU/lb of heating value.
The units in this example
The SI measure of specific energy or heating value — how much energy a kilogram of fuel releases.
- 1 MJ/kg ≈ 429.9 BTU/lb
- 1 MJ/kg ≈ 238.8 kcal/kg
- 1 MJ/kg = 1,000 kJ/kg
- Diesel ≈ 45 MJ/kg
The US measure of fuel heating value, used in oil, gas and coal energy tables.
- 1 BTU/lb ≈ 0.002326 MJ/kg
- 1,000 BTU/lb ≈ 2.326 MJ/kg
- Coal ≈ 12,000 BTU/lb
- Gasoline ≈ 20,000 BTU/lb