Diffraction Grating Calculator

What This Calculator Does

A diffraction grating splits light into its component wavelengths (or diffracts a single wavelength into specific angles) based on the spacing of its lines. This calculator finds the diffraction angle for a given order.

The Grating Equation

d sinθ = mλ, where d is the spacing between grating lines (the inverse of lines per unit length), θ is the diffraction angle, m is the diffraction order (an integer), and λ is the wavelength of light.

If sinθ would exceed 1, no diffraction maximum exists at that order for the given wavelength and grating — the tool flags this case.