Wavelength Color Calculator - Calculator Academy

Calculate the visible color for a wavelength in nanometers, micrometers, meters, or angstroms, from violet through red or outside the spectrum.

What is a Wavelength Color?

“Wavelength color” refers to the approximate color we perceive from monochromatic (single-wavelength) visible light. The visible light spectrum is commonly taken as approximately 380 nanometers (violet) to 750 nanometers (deep red), though the exact boundaries vary by source and by human sensitivity. In general, shorter wavelengths are perceived as blue/violet, while longer wavelengths are perceived as orange/red. Note that many real-world light sources are mixtures of wavelengths, so their perceived color is not determined by a single wavelength.

How to Calculate Wavelength Color?

The following steps outline how to determine the approximate visible color from a wavelength by converting units (if needed) and comparing the result to standard wavelength ranges.

First, determine the wavelength (λ) of the light.
If necessary, convert the wavelength into nanometers (nm).
Compare the wavelength to typical visible-spectrum bands (approx.): violet 380–450 nm, blue 450–495 nm, green 495–570 nm, yellow 570–590 nm, orange 590–620 nm, red 620–750 nm.
The band that contains your wavelength is the corresponding color name. If it is outside roughly 380–750 nm, it is outside the visible spectrum.
Check your answer with the calculator above.

Example Problem:

Use the following variables as an example problem to test your knowledge.

wavelength (λ) = 500 nm

maximum visible wavelength (λ_max) ≈ 750 nm

minimum visible wavelength (λ_min) ≈ 380 nm. Since 500 nm falls in the 495–570 nm range, the corresponding color is green.