How to use the wavelength to frequency calculator
Convert between wavelength and frequency for light and radio waves. Enter wavelength in the field above; the frequency, photon energy are computed instantly and plotted on the chart so you can see how the answer changes.
Formula
Variables
- lam — Wavelength (nm)
Worked example
With wavelength = 550 nm, the calculator gives frequency ≈ 545.0772 THz; photon energy ≈ 2.254258 eV.
Frequently asked questions
What is the formula for the wavelength to frequency calculation?
Frequency (THz) = CLIGHT / (lam × 1e-9) / 1e12. Photon energy (eV) = HPLANCK × CLIGHT / (lam × 1e-9) / QE. Here lam is wavelength (nm).
What inputs do I need for the wavelength to frequency 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 this 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 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.