Photon Energy & Wavelength Calculator

Convert between photon energy, wavelength, and frequency instantly — type into any field and the other two update live, from radio waves to gamma rays.

Photon converter

Electric-field oscillation, colored by this photon's spectral region — schematic only. Cycle count and scroll speed are illustrative (faster for higher-frequency light); a single photon's energy comes from its frequency, not the wave's amplitude, which is arbitrary here.

Region of the spectrumVisible

A photon’s energy, wavelength, and frequency aren’t three independent properties — they’re three ways of describing the same thing. Fix any one of them and the other two follow immediately. That single relationship is why an X-ray telescope reports counts in keV while a radio telescope reports frequency in GHz and an optical astronomer talks in nanometres: it’s all the same electromagnetic spectrum, just read off in whichever unit is most convenient for that regime.

The physics

Two equations connect all three quantities. First, every wave obeys the universal relation between wavelength, frequency, and the speed of light:

c=λfc = \lambda f

Second, Planck’s relation ties a photon’s energy directly to its frequency (equivalently, its wavelength):

E=hf=hcλ,h≈6.626×10−34 J⋅sE = hf = \frac{hc}{\lambda}, \qquad h \approx 6.626 \times 10^{-34}\ \text{J·s}

Because $E$ and $f$ both scale directly with each other, and $\lambda$ scales inversely with them, higher-energy photons always mean shorter wavelengths and higher frequencies — a gamma ray isn’t a “stronger” radio wave, it’s the same phenomenon at the opposite end of an enormous logarithmic scale. The converter above applies these two equations both ways, so editing any of the three fields instantly recomputes the other two.