How to use the photon momentum calculator
Find the momentum carried by a single photon from its wavelength. Enter wavelength in the field above; the photon momentum, photon momentum in ev/c are computed instantly and plotted on the chart so you can see how the answer changes.
Common searches this calculator answers include “photon momentum”, “light momentum”, “p = h over lambda”, “calculate photon momentum”, “find photon momentum”.
Formula
Variables
- lam — Wavelength (nm)
Worked example
With wavelength = 500 nm, the calculator gives photon momentum ≈ 1.3252 × 10⁻²⁷ kg·m/s; photon momentum in ev/c ≈ 2.479684 eV/c.
Frequently asked questions
What is the photon momentum calculator used for?
Find the momentum carried by a single photon from its wavelength. It helps with questions such as “photon momentum”, “light momentum”, “p = h over lambda”.
What is the formula for the photon momentum calculation?
Photon momentum (kg·m/s) = HPLANCK / (lam × 1e-9). Photon momentum in eV/c (eV/c) = HPLANCK × CLIGHT / (lam × 1e-9) / QE. Here lam is wavelength (nm).
What inputs do I need for the photon momentum calculator?
You need wavelength in nm. Each field is pre-filled with a typical example so you can see how the result responds as you edit the numbers.
How do I use the photon momentum calculator?
Type values into the input fields. Results and the chart update instantly. Use Reset to restore the example values, Copy results to paste them elsewhere, or Share to copy a link that preserves your inputs.
Is the photon momentum result exact?
Calculations use standard formulas and double-precision arithmetic, then display about seven significant figures. Real-world measurements carry uncertainty, so treat results as estimates unless your inputs are exact.