What This Calculator Does
This tool converts the frequency of an electromagnetic wave into its corresponding wavelength using the fundamental relationship \(\lambda = c / f\), where c is the speed of light in a vacuum (299,792,458 m/s). It works for any part of the spectrum — radio, microwave, infrared, visible light, ultraviolet, and beyond.
How to Use It
Enter your frequency value, then pick the unit (Hz, kHz, MHz, GHz, or THz). The calculator converts the frequency to hertz, divides the speed of light by it, and returns the wavelength in both meters and nanometers. Nanometers are most useful for visible light (roughly 380–700 nm).
The Formula Explained
An electromagnetic wave's speed in a vacuum is constant, so frequency and wavelength are inversely proportional. Rearranging the wave equation \(c = \lambda \times f\) gives:
$$\lambda = \frac{c}{f}$$Higher frequencies produce shorter wavelengths, and lower frequencies produce longer ones.
Worked Example
Consider a 100 GHz signal. First convert to hertz: \(100 \times 10^{9} = 1 \times 10^{11}\ \text{Hz}\). Then $$\lambda = \frac{299{,}792{,}458}{1 \times 10^{11}} \approx 0.002998\ \text{m}$$ or about 2.998 mm — a typical millimeter-wave wavelength.
FAQ
Does this account for materials other than vacuum? No — it uses the vacuum speed of light. In a medium, divide the result by the refractive index.
What is the wavelength of green light at 540 THz? \(\lambda = \frac{299{,}792{,}458}{5.4 \times 10^{14}} \approx 555\ \text{nm}\), which appears green.
Can I use it for radio frequencies? Yes. For example, an FM station at 100 MHz has a wavelength of about 3 meters.
