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.