# Stefan Boltzmann Law Calculator

Stefan Boltzmann Law Calculator is a handy, flexible and free tool that helps to determine the power radiated from a body at a high temperature. You just need to provide inputs such as the surface area, temperature, material type and emissivity to get the radiated power easily.

### How to Find Power Radiation?

Get the step by step process to calculate the power radiation.

- Get the surface area, temperature and material.
- Multiply the emissivity by the Stefan Boltzmann constant, and surface.
- Find the fourth power of the temperature.
- Multiply the product from step 2 by the result from above steps to check the power.

### Stefan Boltzmann Law

Stefan Boltzmann Law states that the power radiated from a black body is directly proportional to its temperature raised to the fourth power.

The thermal radiation formula is

**P = σ ε A TΓü┤**

Where,

P is the power of the body's temperature

σ is the Stefan Boltzmann constant and its value is 5.670367 x 10-8

ε is the emissivity

A is the surface area of the body

T is the body temperature

**Example**

**Question: A black body emitts of 0.1 and its area is 200 m² at 500 K. Find at what rate does it radiate the energy?**

**Solution:**

Given that

Temperature T = 500 K

Surface area A = 200 m²

Emittivity ε = 0.1

Radiated energy P = σ ε A TΓü┤

P = 5.670367 x 10-8 x 0.1 x 200 x (500)

= 113.40734 x 625

= 7.08 x 104 W

Therefore, the radiated energy is 7.08 x 104 W.

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### Frequently Asked Questions on Stefan Boltzmann Law Calculator

**1. Define Stefan Boltzmann Law?**

Stefan Boltzmann law states that the amount of radiation energy emitted per unit time from an area of a black body at absolute temperature is directly proportional to the fourth power of the temperature.

**2. What is the value of Stefan Boltzmann constant?**

Stefan Boltzmann constant value is approximately 5.67 x 10-8 W/m²K4

**3. A body emissivity (e = 0.75), the surface area of 300 cm2 and temperature is 227°C are kept in a room at temperature 27°C. Calculate the initial value of net power emitted by the body using the Stephens Boltzmann law.**

Emmissivity e = 075

surface area A = 300 cm² = 3 x 10-2 m²

Power P = σ ε A TΓü┤

= 0.75 x 5.67 x 10-8 x 3 x 10-2 x [(500)4 - (300)4]

= 69.4 Watts

**4. What is the relationship between the Stefan-Boltzmann law and Wien's law?**

Wine's law tells the relationship between the wavelength of maximum intensity a blackbody emits and its temperature. While the Stefan Boltzmann law tells that the energy radiated from a blackbody is proportional to the fourth power of its temperature.