Stefans Law Calculator

What is Stefan's Law?

Stefan's Law, also known as Stefan-Boltzmann Law, states that the total energy radiated per unit surface area of a black body across all wavelengths per unit time (known as the radiant exitance or emissive power) is directly proportional to the fourth power of the black body's absolute temperature T.

How to Use This Calculator

1. Enter the absolute temperature of the black body in Kelvin (T). Note that absolute temperature starts from absolute zero (-273.15°C).
2. Enter the surface area of the black body in square meters (A).
3. Click the "Calculate" button to compute the total energy radiated.
4. The result will be displayed in Watts (W).

Practical Applications

Stefan's Law has many practical applications including:

• Calculating the heat loss from buildings
• Determining the temperature of stars
• Understanding heat radiation in industrial processes
• Designing thermal systems and appliances

Example

If a black body with a surface area of 1 square meter is maintained at a temperature of 300 Kelvin, the total energy radiated would be:

P = (5.67 × 10⁻⁸ W m⁻² K⁻⁴) × 1 m² × (300 K)⁴ = 453.6 Watts