Stefan-Boltzmann Calculator
Calculate thermal radiation power from a surface using the Stefan-Boltzmann law: P = εσT⁴A.
Use the Stefan-Boltzmann Calculator
Input Parameters
Temperature in Kelvin must be > 0.
Subtract absorption from surroundings at ambient temperature.
Radiated Power
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Watts (W)
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Kilowatts (kW)
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Megawatts (MW)
Surface Intensity
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W / m²
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Temperature (K)
Formula Breakdown
Enter values and click Calculate to see results.
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Summary
The Stefan-Boltzmann calculator applies the Stefan-Boltzmann law (P = εσT⁴A) to compute the total power radiated by a surface at a given temperature. It accounts for emissivity — a material property between 0 and 1 — and the surface area of the radiating body. This is essential in thermodynamics, astrophysics, engineering heat transfer, and climate science.
How it works
- Enter the surface temperature in Kelvin (or switch to Celsius/Fahrenheit).
- Set the emissivity value between 0 (perfect reflector) and 1 (perfect blackbody).
- Enter the surface area in square meters.
- The calculator applies P = εσT⁴A using σ = 5.670374419 × 10⁻⁸ W m⁻² K⁻⁴.
- Results show radiated power in watts, kilowatts, and megawatts.
Use cases
- Estimate heat loss from industrial furnaces and kilns.
- Calculate stellar luminosity from surface temperature and radius.
- Analyze thermal radiation in building energy audits.
- Design radiative cooling systems for electronics.
- Study climate and planetary energy balance.
- Verify thermal sensor readings in engineering experiments.
Frequently Asked Questions
Last updated: 2026-09-30 ·
Reviewed by Nham Vu