Energy to Wavelength

λ = hc / E

How to Use This Calculator

Enter photon energy and choose the unit (eV or J). The tool computes the corresponding wavelength in nanometers.

Formula

λ = hc / E

Where h is Planck's constant and c is the speed of light.

Frequently Asked Questions

Which spectrum range?

Energy determines wavelength: higher energy → shorter wavelength. Visible light spans ~1.65 eV (750 nm) to ~3.26 eV (380 nm).