Energy to Wavelength Calculator

Convert photon energy to its wavelength.

Wavelength (nm) 495.94
Frequency (THz) 604.5

Formula: λ = h·c ÷ E

Step-by-step with your numbers:
1. Values used:
2. Photon energy = 2.5 eV
3.
4. Wavelength = 495.94nm
5. Frequency = 604.5THz
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Convert a photon's energy into the wavelength of light it corresponds to.

The math behind it

λ = h·c ÷ E. A handy shortcut: λ(nm) ≈ 1240 ÷ E(eV).

Worked example

2.5 eV → about 496 nm (blue-green).

FAQ

What's the 1240 rule?

λ in nm ≈ 1240 divided by energy in eV — a quick photon conversion.