Photon Energy Calculator — Formula
## Photon Energy
A photon's energy is proportional to its frequency and inversely proportional to its wavelength.
### Formula
**E = h * f = h * c / lambda**
where h = 6.626 x 10^-34 J·s is Planck's constant and c = 3 x 10^8 m/s. To convert to electron volts, divide by 1.602 x 10^-19.
A photon's energy is proportional to its frequency and inversely proportional to its wavelength.
### Formula
**E = h * f = h * c / lambda**
where h = 6.626 x 10^-34 J·s is Planck's constant and c = 3 x 10^8 m/s. To convert to electron volts, divide by 1.602 x 10^-19.
Esempio Risolto
A green photon with wavelength 550 nm.
- f = c / lambda = 3e8 / 550e-9 = 5.45e14 Hz
- E = h * f = 6.626e-34 * 5.45e14
- E = 3.614e-19 J
- E = 3.614e-19 / 1.602e-19 = 2.257 eV