Planck's Law Calculator
Calculate the spectral radiance of blackbody radiation at any temperature and wavelength.
Results
Spectral Radiance B_λ: 2.6376e+13 W/(m²·sr·m)
Spectral Radiance B_λ: 2.6376e+4 W/(m²·sr·nm)
Energy Density u_λ: 1.1056e+6 J/(m³·m)
Exponent (hν/kT or hc/λkT): 4.9802
Planck's Radiation Law
Wavelength form:
B_λ(T) = (2hc²/λ⁵) × 1/(e^(hc/λkT) - 1)
Frequency form:
B_ν(T) = (2hν³/c²) × 1/(e^(hν/kT) - 1)
h = 6.626 × 10⁻³⁴ J·s (Planck constant)
k = 1.381 × 10⁻²³ J/K (Boltzmann constant)
c = 2.998 × 10⁸ m/s (speed of light)