# Stefan Boltzman Law

Written by Jerry Ratzlaff on . Posted in Thermodynamics

## Stefan Boltzmann Law

Stefan Boltzman Law states that the total energy radiated from black body radiation that is emitted by a surface is porportional to the fourth power of its absolute temperature.

### Stefan Boltzmann Law Formula

$$P = \epsilon \sigma T_a^4 A$$

Where:

$$P$$ = radiate energy

$$\sigma$$ = Stefan Boltzmann Constant

$$T_a$$ = absolute temperature

$$\epsilon$$ (Greek symbol epsilon) = emissivity of the material

$$A$$ = area of the emitting body

## Stefan Boltzmann Constant

Stefan Boltzman Constant ( $$\sigma$$ ) (also called Stefan Constant) has a value of $$5.670373 \;\dot\;\; 10^{-8} \; W/m^2/K^4$$