Photon Energy Calculator

Calculate the energy of a photon from its frequency or wavelength.

Photon Parameters

Hz
nm

Photon Energy Formulas

The energy of a photon is directly proportional to its frequency and inversely proportional to its wavelength.

From Frequency:

E = hf

From Wavelength:

E = hc / λ

Where:

  • E = Photon Energy (Joules or electronvolts)
  • h = Planck's Constant (6.626 × 10-34 J·s)
  • f = Frequency (Hz)
  • c = Speed of Light in vacuum (2.998 × 108 m/s)
  • λ = Wavelength (meters)

Photon Energy Examples

Light Type Wavelength (nm) Frequency (Hz) Energy (eV)
Red Light7004.28 × 10141.77
Green Light5505.45 × 10142.25
Blue Light4506.66 × 10142.76
UV Light2501.20 × 10154.96
X-ray0.13.00 × 101812.4 keV

Frequently Asked Questions

What is a photon?

A photon is a quantum of light and all other forms of electromagnetic radiation. It is the elementary particle of light, and it always moves at the speed of light in a vacuum.

How is photon energy calculated from frequency?

The energy of a photon (E) is directly proportional to its frequency (f). The formula is E = hf, where h is Planck's constant (approximately 6.626 × 10⁻³⁴ J·s).

How is photon energy calculated from wavelength?

Since frequency (f) and wavelength (λ) are related by the speed of light (c) (f = c/λ), the photon energy can also be calculated as E = hc/λ, where c is the speed of light in a vacuum (approximately 3 × 10⁸ m/s).