Enter the total energy (J) and the total mass (kg) into the Calculator. The calculator will evaluate the Energy Per Unit Mass. 

Energy Per Unit Mass Formula

EPM = E / M


  • EPM is the Energy Per Unit Mass (J/kg)
  • E is the total energy (J)
  • M is the total mass (kg)

To calculate Energy Per Unit Mass, divide the energy by the mass in kilograms.

How to Calculate Energy Per Unit Mass?

The following steps outline how to calculate the Energy Per Unit Mass.

  1. First, determine the total energy (J). 
  2. Next, determine the total mass (kg). 
  3. Next, gather the formula from above = EPM = E / M.
  4. Finally, calculate the Energy Per Unit Mass.
  5. After inserting the variables and calculating the result, check your answer with the calculator above.

Example Problem : 

Use the following variables as an example problem to test your knowledge.

total energy (J) = 700

total mass (kg) = 1000


What is Energy Per Unit Mass?

Energy Per Unit Mass is a measure that quantifies the amount of energy (in joules) per unit of mass (in kilograms). It’s a way to express how much energy is stored or required per kilogram of a substance or object.

Why is calculating Energy Per Unit Mass important?

Calculating Energy Per Unit Mass is crucial in various fields such as physics, engineering, and materials science. It helps in understanding the efficiency of fuel sources, the performance of batteries, and the properties of different materials.

Can Energy Per Unit Mass be applied to any form of energy?

Yes, Energy Per Unit Mass can be applied to any form of energy, including thermal, electrical, chemical, and nuclear energy. The key is to accurately measure or calculate the total energy and the mass to which that energy is associated.

How does the concept of Energy Per Unit Mass relate to energy density?

Energy Per Unit Mass is closely related to the concept of energy density, which is often expressed as the amount of energy per unit volume. However, Energy Per Unit Mass specifically refers to the energy content per unit mass, making it a useful measure for comparing the energy content of materials with different densities.