Enter the absolute temperature (K) and Stefan’s Constant (5.67*10^-8 W/m^2/K^4) into the calculator to determine the Radiant Energy. 

Radiant Energy Formula

The following equation is used to calculate the Radiant Energy.

RE = σ * T^4
  • Where RE is the Radiant Energy (Joules)
  • T is the absolute temperature (K) 
  • σ is the Stefan’s Constant (5.67*10^-8 W/m^2/K^4) 

To calculate the radiant energy, multiply Stefan’s Constant by the absolute temperature raised to the power of 4.

How to Calculate Radiant Energy?

The following example problems outline the steps and information needed to calculate Radiant Energy.

Example Problem #1

  1. First, determine the absolute temperature (K). In this example, the absolute temperature (K) is determined to be 5 .
  2. Next, determine the Stefan’s Constant (5.67*10^-8 W/m^2/K^4)
  3. Finally, calculate the Radiant Energy using the formula above: 

RE = σ * T^4

Inserting the values from above and solving the equation yields: 

RE = 5.67*10^-8 * 5^4 = .0000354 (Joules)


Example Problem #2

Using the same method as above, first, we need to measure or determine the variables required by the equation. For this example problem, these are provided as follows: 

absolute temperature (K) = 6

Stefan’s Constant (5.67*10^-8 W/m^2/K^4)

Enter these given values into the calculator or above yields: RE = σ * T^4 = .0000734 (Joules)