Enter the Stefan-Boltzmann constant and the thermodynamic temperature into the calculator to determine the total radiation energy emitted per unit surface area of a black body in unit time. This calculator can also evaluate any of the variables given the others are known.

## Stefan’s Law Formula

The following formula is used to calculate the total radiation energy emitted per unit surface area of a black body in unit time according to Stefan’s Law.

E = σ * T^4

Variables:

- E is the total radiation energy emitted per unit surface area of a black body in unit time (W/m^2)
- σ is the Stefan-Boltzmann constant (5.67 x 10^-8 W/m^2K^4)
- T is the thermodynamic temperature of the black body (K)

To calculate the total radiation energy emitted per unit surface area of a black body in unit time, multiply the Stefan-Boltzmann constant by the fourth power of the thermodynamic temperature of the black body.

## What is Stefan’s Law?

Stefan’s Law, also known as Stefan-Boltzmann Law, is a principle in physics that states that the total radiation energy emitted per unit surface area of a black body in unit time (also known as the black-body radiant emittance) is directly proportional to the fourth power of the black body’s thermodynamic temperature. This law is used in many areas of physics to calculate the amount of energy that is radiated by a black body, which is an idealized physical body that absorbs all incident electromagnetic radiation.

## How to Calculate Stefan’s Law?

The following steps outline how to calculate the Stefan’s Law using the given formula:

- First, determine the value of the Stefan-Boltzmann constant (σ). It is given as 5.67 x 10^-8 W/m^2K^4.
- Next, determine the thermodynamic temperature of the black body (T) in Kelvin (K).
- Next, substitute the values of σ and T into the formula E = σ * T^4.
- Finally, calculate the total radiation energy emitted per unit surface area of the black body in unit time (E) in W/m^2.
- 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:

Stefan-Boltzmann constant (σ) = 5.67 x 10^-8 W/m^2K^4

Thermodynamic temperature of the black body (T) = 300 K