Thermal Radiation Calculator (Stefan–Boltzmann)

Estimate net radiated power: P = εσA(T⁴ − Tenv⁴). Optional: energy over time.

Typical emissivities (surface-dependent).
0 = perfect reflector, 1 = perfect emitter.
Area radiating to the environment.
Converted to Kelvin internally.
Radiation depends on absolute temperature (T⁴).
hours
If provided, energy = P × time (kWh).
P = εσA(T⁴ − Tenv⁴)
σ = 5.670374419×10⁻⁸ W/(m²·K⁴)
Net P can be negative if object is cooler than environment.