# How to calculate frequency from wavelength

The relationship between frequency and wavelength is a fundamental concept in the field of physics, particularly in the study of electromagnetic waves. In this article, we will explore what frequency and wavelength are, their relationship, and how to calculate frequency from wavelength using a simple formula.

**Defining Frequency and Wavelength:**

**1. Frequency (f):**

Frequency refers to the number of oscillations or cycles that occur per unit of time. In the context of electromagnetic waves, it represents the number of complete wave cycles passing through a given point in one second. The unit of frequency is Hertz (Hz).

**2. Wavelength (λ):**

Wavelength is the distance between two consecutive points in a wave which are in the same phase, such as two consecutive crests or troughs. In electromagnetic waves, this distance represents one complete cycle of the sinusoidal variation in the electric and magnetic fields. The unit most commonly used for wavelength is meters (m).

**The Relationship between Frequency and Wavelength:**

Frequency (f) and wavelength (λ) are inversely proportional in electromagnetic waves. This means that as the frequency increases, the wavelength decreases and vice versa. Their relationship can be represented through the equation:

c = f * λ

In this equation, “c” stands for the speed of light in a vacuum, which has a constant value of approximately 3.00 x 10^8 meters per second (m/s). The product of frequency and wavelength equals this constant value.

**Calculating Frequency from Wavelength:**

To calculate frequency from wavelength, you can rearrange the equation mentioned above as follows:

f = c / λ

Now follow these steps to calculate frequency:

1. Measure or determine the wavelength (λ) of the wave.

2. With “c” being a constant value (3.00 x 10^8 m/s), divide c by the measured or given wavelength (λ).

3. The result will be the frequency (f) of the wave in Hertz (Hz).

**Example:**

Let’s calculate the frequency of an electromagnetic wave with a wavelength of 500 nanometers (nm).

First, convert the wavelength from nanometers to meters:

500 nm = 500 x 10^-9 m = 5.00 x 10^-7 m

Now, use the rearranged formula:

f = c / λ

f = (3.00 x 10^8 m/s) / (5.00 x 10^-7 m)

f ≈ 6.00 x 10^14 Hz

So, the frequency of the electromagnetic wave with a wavelength of 500 nm is approximately 6.00 x 10^14 Hz.

**Conclusion:**

Calculating frequency from wavelength is a simple and essential process for understanding electromagnetic waves and various applications in physics, astronomy, communication technology, and more. By using the equation f = c / λ, one can easily determine the frequency of any electromagnetic wave when its wavelength is known.