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Calcimator

Planck Bλ

Blackbody spectral radiance per unit wavelength (SI).

Inputs

Results

B_λ (W·sr⁻¹·m⁻³)

26,375,669,866,614.81

How to Use This Calculator
  1. Enter the blackbody temperature T (K) -- Sun surface ~5778 K, room temperature ~293 K.
  2. Enter the wavelength lambda (m) -- visible light: 380-700 nm = 3.8e-7 to 7e-7 m.
  3. Review spectral radiance in W per sr per m3.
  4. Sweep wavelength across the visible spectrum to see how radiance peaks shift with temperature (Wien's law).
  5. Compare spectral radiance at different temperatures to understand why hotter objects appear bluer.
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