Light Frequency Calculator
Compute light frequency from wavelength (or vice versa) with f = c/λ, then see its spectrum color, electromagnetic spectrum band, photon energy E = hf, and wavenumber — all with the exact speed of light c = 299,792,458 m/s.
Marker position on the logarithmic scale 10⁻¹² m … 10⁶ m (gamma rays → radio waves).
Verified example: 550 nm green light
| Quantity | Value |
|---|---|
| Wavelength λ | 550 nm = 5.50×10⁻⁷ m |
| Frequency f = c/λ | 545.08 THz (545.07719636363636 THz) |
| Color | Green (range 495–570 nm) |
| EM band | Visible light |
| Photon energy E = hf | 3.6117×10⁻¹⁹ J = 2.2543 eV |
| Wavenumber 1/λ | 18,181.8 cm⁻¹ |
The numbers above were recomputed from scratch with 60-digit precision arithmetic (exact constants c = 299792458 m/s, h = 6.62607015×10⁻³⁴ J·s, 1 eV = 1.602176634×10⁻¹⁹ J).
Frequently asked questions
What is the frequency of light with a 550 nm wavelength?
f = c/λ = 299792458 / 5.50×10⁻⁷ = 545,077,196,363,636.36 Hz, or 545.08 THz. A 550 nm wavelength falls in the green color range (495–570 nm) in the visible light band.
What is the photon energy of 550 nm green light?
E = hf = 6.62607015×10⁻³⁴ × 545,077,196,363,636.36 ≈ 3.6117×10⁻¹⁹ J. Divided by 1.602176634×10⁻¹⁹ J/eV, the result is 2.2543 eV per photon.
What is the wavelength range of each visible light color?
Violet 380–450 nm, blue 450–495 nm, green 495–570 nm, yellow 570–590 nm, orange 590–620 nm, red 620–750 nm (source: Wikipedia, Visible spectrum article). Color boundaries are approximate because the spectrum is continuous.
How does this calculator differ from the Wavelength to Frequency Calculator?
This tool is framed specifically for light: visible color presets with verified wavelength ranges, EM spectrum band classifier (gamma rays to radio waves), spectrum position marker, photon energy, and wavenumber. The Wavelength to Frequency Calculator is a general EM converter with Hz unit breakdown, period, angular frequency, and mass equivalent — with no color presets or band classifier.
What is the wavelength for a 10 MHz frequency?
λ = c/f = 299792458 / 10,000,000 = 29.9792458 meters — in the radio wave band.
What is wavenumber and what is its value for 550 nm?
Wavenumber is the reciprocal of wavelength (1/λ), usually expressed in cm⁻¹. For λ = 550 nm: 1/(5.50×10⁻⁷ m) = 1,818,181.8 m⁻¹ = 18,181.8 cm⁻¹.
Why does frequency rise when wavelength falls?
Because f = c/λ with c constant, they are inversely proportional: half the wavelength produces twice the frequency — for example 275 nm has a frequency of about 1,090.15 THz.
Free tool by NRTechStudio