Thermal energy calculator


How to use our thermal energy calculator?

The thermal energy calculator gives directly the value when the mass, the specific heat and the change of temperature is given in the calculator.

When it is the value of the thermal energy that is changed, the calculator will give the change in temperature for this value of thermal energy.

Table of contents:

What is the thermal energy?

The thermal energy is the quantity of energy of a substance in function of the quantity of particles of this substance (the mass) and its temperature.

Thermal energy and heat?

The heat is the transfer of thermal energy between two media of different temperature, from the hotter media to the colder media.

Thermal energy formula

To calculate the quantity of thermal energy stocked by a substance, the following equation is used:

Q = m x c x ΔT


  • Q represents the quantity of thermal energy (J)
  • m represents the mass of the substance (kg)
  • c represents the specific heat capacity (also called the massic heat capacity) of the substance (J kg-1 °K-1). In other words, it corresponds to the quantity of energy provided to 1 kg of this substance to increase its temperature from 1°K.
  • ΔT represents the change of temperature (ΔT = Tf – Ti) (°K). It is important to note that a variation of 1 °K is equal to a variation of 1°C. So the change of temperature is the same in Kelvin and Celsius.

In this formula, a positive change of temperature means that the substance has absorbed heat. On the opposite, a negative change of temperature means a loss of heat, which gives a release of heat.


The SI unit for the thermal energy is the joule (J). However, Watt-hours and electron volt are also common.


The common symbol for the thermal energy is the letter Q.

The specific heat capacity

The specific heat capacity (also called the massic heat capacity) is a typical property of a substance. It gives the capacity of a substance to absorb or free heat. Its SI unit is (J kg-1 °K-1)

Other calculors, converters, tools and tables in this category