Wavelength measures the distance from one point of a wave to the same point on an adjacent wave, whereas the frequency represents how many waves are produced from the source per second. Wavelengths are measured in nanometers and frequencies are measured in hertz or waves per second. When wavelength decreases, frequency increases because the distance between waves is shorter.
Calculating both properties uses a simple formula. The wavelength equals the velocity (v) times the period (T) of the wave. The period is the time between individual waves. The frequency can be substituted for the period of the wave by inverting the period figure (1/T). The relationship between wavelength and frequency is the formula velocity equals frequency times wavelength, which means frequency is velocity divided by the wavelength, and the wavelength is velocity divided by frequency. This is called an inverse relationship.
As an example of this formula, imagine a wavelength of 2 feet traveling at 6 feet per second. That means three waves pass by a particular point every second, or six divided by two. The frequency is three waves per second, or 3 Hz.
Frequencies of strong electromagnetic waves are often measured in kilohertz, megahertz and gigahertz. Kilohertz means 1,000 waves per second, megahertz is 1 million waves and gigahertz is 1 billion waves passing by per second. Radio stations broadcast around 100 MHz, whereas wireless computer networks are close to 2.4 GHz.