Wien's Displacement Law Calculator

About this calculator

This calculator finds the peak emission wavelength of a blackbody radiator from its temperature using Wien's displacement law: λmax = b / T, where b is Wien's displacement constant (≈2.898 × 10⁻³ m·K) and T is the absolute temperature in kelvin. As an object gets hotter, its peak wavelength shifts to shorter (bluer) wavelengths.

Astronomers use it to estimate a star's surface temperature from its color (or vice versa), and physics students use it to connect thermal radiation to the visible spectrum — explaining, for instance, why a heated metal glows red before white-hot. Enter a temperature to get the peak wavelength, or a wavelength to back out the temperature.