Photon Energy Calculator



This application allows you to calculate the energy of a single photon based on its wavelength or frequency using the well-known quantum formula.
It is useful for physics students, technicians, enthusiasts of optics, and quantum disciplines.

How it works

The user can choose between two modes:

  • Enter the wavelength (in nm) of the photon;
  • Enter the frequency (in Hz) of the photon.

The app automatically calculates according to the relationship: E=h⋅fE = h cdot fE=h⋅f

or E=h⋅cλE = frac{h cdot c}{lambda}E=λh⋅c​

where:

The energy is provided in joules (J) and electronvolts (eV), two common units in radiation physics.

What it’s for

This calculator is particularly useful for:

  • Estimating the energy associated with visible, ultraviolet, X-ray, or gamma-ray photons;
  • Understanding the relationship between wavelength/frequency and energy;
  • Preparing laboratory reports or educational exercises on energy quantization;
  • Analyzing phenomena such as the photoelectric effect or optical absorption.

Interpreting the results

The user will see:

  • The value of the entered wavelength or frequency;
  • The corresponding energy in Joules;
  • The corresponding energy in electronvolts (eV);
  • A button to copy the results and use them in documents or spreadsheets.

Practical example

  • Wavelength: 500 nm → Frequency approximately 6.00×10^{14} Hz → Energy approximately 2.48 eV (≈ 3.98×10^{-19} J).
  • Frequency: 1.00×10^{15} Hz → Energy approximately 4.14 eV (≈ 6.63×10^{-19} J).

Warnings

The calculation provides a theoretical estimate based on monochromatic light and ideal conditions. In reality:

  • The wavelength can vary depending on the medium;
  • The energy can be influenced by quantum or relativistic effects;
  • Real materials exhibit absorption, scattering, and bandwidth effects.

Use the results as educational reference or indicative value, and not as absolute numbers in highly precise experimental setups.

FAQ – Frequently Asked Questions

1. What formula is used for the calculation?
The formula used is E=h⋅fE = h cdot fE=h⋅f or E=h⋅cλE = frac{h cdot c}{lambda}E=λh⋅c​. Wikipedia+1

2. Why is the energy greater for shorter wavelengths?
Because E is inversely proportional to λ: the shorter the wavelength, the higher the frequency, thus greater the energy. sinovoltaics.com+1

3. What does 1 eV represent?
An electronvolt is the energy gained by an electron accelerated through a potential difference of 1 volt. Approximately 1.602×10^{-19} J. pveducation.org

4. Can I use the calculator for photons in a medium other than vacuum?
No, this version assumes the speed of light in vacuum and ideal conditions. In mediums, speed and refractive index affect the calculations.

5. What units can I obtain?
The app displays energy in both Joules (J) and electronvolts (eV) for greater convenience.