What is Wavelength : Equation and Its Working

A wave occurs when energy travels from one place to another. For instance, consider a pool, if we jump into the pool, wave’s start flowing from the spot to all around the swimming pool. These waves are an outcome of the flow of energy and this will move across the swimming pool. Here we can observe that the energy only moves not the water in the pool. Whenever the molecules of water move up & down at an exact angle toward the path of the wave then it is called a transverse wave. Similarly, a light wave occurs when energy travels which is composed of electric as well as magnetic fields. Sometimes, it is called electromagnetic radiation. The size of the wave can be calculated in wavelengths and the wavelength can be measured by deciding the space between two points on the waves like peak-to-peak otherwise trough-to-trough.

What is Wavelength?

The definition of wavelength is the distance between two equal contiguous points within a signal. Normally, the measurement of wavelength can be done among two individual points like two adjoining points otherwise channels within a waveform. For different types of waves, wavelengths can be calculated. They are most exactly calculated in sinusoidal waves because these waves have a repetitive and smooth oscillation. The wavelength diagram is shown below.


If the two signals or waves traveling at an equal speed with high frequency then it will have a shorter wavelength. Similarly, if the two signals or waves traveling at the equal speed with low frequency then it will have dissimilar wavelengths.

Wavelength Equation

The wavelength can be calculated by using the following wavelength formula.

λ = v / ƒ

In the above equation,


The ‘λ’ symbol is used to denote the wavelength in mathematics as well as physics.

The ‘v’ symbol denotes velocity

The ‘ƒ’ symbol denotes wavelength frequency.

The electromagnetic spectrum includes different waves like light waves & radio waves. These waves have much lesser wavelengths compare with sound waves. So, the wavelengths of these waves are normally calculated in nanometers or millimeters rather than meters or centimeters.

Wavelength Unit

The wavelength symbol is commonly expressed with lambda (λ) and it is a Greek letter.

The SI unit of wavelength is meter and it is represented by a symbol (m). The fractions otherwise multiples of a meter is used while calculating wavelength. Especially, when wavelengths have large property then exponential powers of 10 are used. Similarly, when there are fewer wavelengths then they are expressed like negative exponentials.


  • The sound wavelength decides its pitch, as well as the light wavelength, decides its color.
  • The visible light’s wavelengths can be extended from 700 nm – 400 nm.
  • The audible sound wavelength can range from 17 mm – 17 m. This sound is much longer than visible light.

Wavelength in Wireless Networks

In wireless networking, the concepts of frequencies are frequently discussed. This is also a significant feature within the networks like Wi-Fi. The working of this can be done using five frequencies in the range of GHz (gigahertz) like 2.4, 3.6, 4.9, 5 and 5.9. The shorter wavelengths mainly occur in higher frequencies & signals which have fewer wavelengths, it has more difficulty while penetrating obstacles such as floors and walls.

Thus, wireless access points mainly operate at higher frequencies with lesser wavelengths. It uses more power for transmitting data at the same speeds as well as distances can be attained by devices like which work at low frequencies using longer wavelengths.

How to Measure Wavelength?

Instruments like optical spectrum analyzers otherwise optical spectrometers are used for identifying wavelengths within the electromagnetic spectrum. These are measured in meters, kilometers, micrometers, millimeters & also lesser denominations which include pic- meters, nano-meters & femtometers.

The latter can be used for measuring lesser wavelengths in the electromagnetic spectrum like UV radiation, gamma rays, and X-rays. On the other hand, radio waves include longer wavelengths which range from 1mm to 100kms based on the frequency.

If the signal frequency ‘f’ is measured in MHz and the wavelength ‘w’ is measured in meters then the wavelength and frequency can be calculated

w = 300/f and equally f = 300/w

The distance amid recurrences within the signals specifies wherever the wavelength is on the electromagnetic radiation spectrum like radio waves within the range of audio & waves within the range of visible light.

Electromagnetic Waves

These waves are a type of energy waves and it includes both the fields like an electric as well as a magnetic field. These waves are dissimilar compare with mechanical waves because they transmit energy as well as travels throughout a vacuum.

The classification of these waves can be done based on their frequency. These waves are used for different purposes in our daily lives. The most significant of these waves are visible light as it allows us to see.


Radio waves include the highest wavelengths compare with all types of electromagnetic waves. They range approximately from centimeters long to numerous miles. These waves are frequently used for data transmitting in different applications like satellite, radio, computer n/w’s and radar.

Microwave signals are smaller than radio signals with wavelengths calculated within centimeters. These are used in communication as they can go through smoke, clouds, as well as light rain.

Infrared waves are located in between microwaves as well as visible light. These waves are categorized into two types like near-infrared & far infrared. Near IR waves are nearer to visible light within a wavelength. These waves are used mainly in television remotes for altering channels. Similarly, far IR waves are away from this light within a wavelength.

The wavelength of the UV waves is shortest compared with visible light. These rays come from the Sun so it causes sunburns. The UV light is mainly used through telescopes such as the Hubble Space Telescope to observe stars in the sky.

X rays include less wavelength compare with UV rays. X-rays were noticed by the German scientist namely ‘Wilhelm Roentgen’. These rays are used to penetrate into the skin as well as the muscle of humans to take X-ray pictures in the medical field.

When the EM wave’s wavelength gets lesser then their energy will increase. The shortest rays are Gamma rays within the spectrum. Sometimes, these rays are used for treating cancer as well as capturing cleared images of diagnostic medicine. These rays are generated within high-energy nuclear blasts & supernovas.

Thus, this is an overview of wavelength and its working. We hope that you have got a better understanding of this concept. Furthermore any queries regarding this concept please give us your feedback by commenting in the comment section below. Here is a question for you, what is wavelength division multiplexing?