Diffraction Grating Calculator

Find the diffraction angle from a grating.

Diffraction angle (°) 19.269

Formula: d·sinθ = m·λ

Step-by-step with your numbers:
1. Values used:
2. Lines per mm = 600 /mm
3. Wavelength = 550 nm
4. Order m = 1
5.
6. Diffraction angle = 19.269°
Did we solve your problem today?

A diffraction grating splits light into its colors at angles set by line spacing.

The math behind it

d·sinθ = m·λ, where d is the slit spacing (1 ÷ lines per metre) and m is the order.

Worked example

600 lines/mm, 550 nm, order 1 → about 19.3°.

FAQ

Why do gratings make rainbows?

Each wavelength diffracts to a slightly different angle.