Fuel Energy per Mass Converter

Convert specific energy and fuel heating value between J/kg, kJ/kg, MJ/kg, calories per gram, and International BTU per pound.

Convert instantly

Enter a value and choose the units. Your answer updates as you type.

Value

From

Result

0.001 Kilojoule per kilogram (kJ/kg)

Quick reference

Joule per kilogram (J/kg)1 base units
Kilojoule per kilogram (kJ/kg)1000 base units
Megajoule per kilogram (MJ/kg)1000000 base units
Calorie per gram (cal/g)4184 base units
International BTU per pound (Btu/lb)2326 base units
Kilowatt-hour per kilogram (kWh/kg)3600000 base units

About the Fuel Energy per Mass Converter

Fuel energy per mass, also called specific energy or gravimetric heating value, compares usable heat with the mass of a fuel. It helps compare batteries, hydrogen, gasoline, biomass, and aviation fuels. This converter uses the thermochemical calorie (4.184 J) and International Table BTU (1,055.05585262 J); for example, 1 MJ/kg equals about 239.006 cal/g.

Convert a laboratory result or datasheet value as you type—for example, 42 MJ/kg is about 18,056.75 BTU/lb. Use the Fuel Energy per Volume & Heat Density Converter for volumetric comparisons, or the Density Converter when converting between mass-based and volume-based fuel properties.

Frequently asked questions

What does MJ/kg measure?

MJ/kg measures energy released or stored per kilogram and is a common unit for fuel heating value and battery specific energy.

How many BTU/lb are in 1 MJ/kg?

One MJ/kg is approximately 429.9226 International BTU per pound.

Is specific energy the same as energy density?

Specific energy is energy per mass; energy density generally means energy per volume, so they are different properties.

Take this calculation further

Browse the converters calculators collection for more tools in this subject.

For a related calculation, use Fuel Energy per Volume & Heat Density Converter to convert volumetric fuel energy and heat density between J/m³, kJ/L, MJ/L, kWh/m³, and International BTU per cubic foot. Alternatively, use Fuel Consumption Converter to convert fuel economy between US mpg, Imperial mpg, liters per 100 km, and kilometers per liter using correct inverse formulas.