This tool converts from Wavelength in nm, um, mm, cm, m, inches or feet to Frequency in Hz, kHz, MHz, GHz.
Formula
Frequency f is given by the formula
f = c/λ
where, c is the speed of light and λ is the wavelength. As the wavelength increases the frequency decreases.
In a vacuum, the speed of light is c = 299,792,458 meters/second. It is slower in other media such as in glass for instance where the speed is 200,000,000 meters/second. Change the value of c in the calculator above to calculate the frequency in this case.
For a fixed value of wavelength, as c increases, so does f.
The picture below shows the wavelength (λ) of a sine wave
Background
The relation between frequency and wavelength is an essential concept in understanding the behavior of waves.
The wavelength is the distance between two consecutive points on a wave, whereas the frequency is the number of oscillations or cycles that occur within a given time period.
Frequency and wavelength are inversely proportional to each other. As the wavelength increases, the frequency decreases, and vice versa. For example, visible light has a higher frequency compared to radio waves, hence it has a shorter wavelength.
This relationship is governed by the equation v = λf, where v represents the wave speed or velocity, λ represents the wavelength, and f represents the frequency. The equation highlights that the wave speed is equal to the product of wavelength and frequency. Additionally, the amplitude of a wave is another significant factor that determines the number of times a wave oscillates within a given time.
In summary, the relation between frequency and wavelength is integral in understanding the behavior and properties of waves.
Frequency and Wavelength in RF Engineering
Most radio engineers are used to referring to regions of the electromagnetic spectrum in terms frequency – for instance the Wi-Fi band is 2.4 GHz and 5 GHz.
The exception is when you get to lower frequencies in HF and VHF. At these bands, hobbyists and technologists refer to wavelength. For instance the 2 meter and 70 cm bands. It can be a little confusing sometimes.
This calculator clears up that confusion to make the conversion between wavelength and frequency easy.