In the world of waves—from light to sound to radio—two properties are fundamentally linked: frequency vs. wavelength. Understanding this relationship is the key to understanding how everything from your Wi-Fi router to the color of the sky works.

The Core Concept: An Inverse Relationship

The relationship between frequency and wavelength is inversely proportional. This sounds complicated, but it's very simple:

• When frequency goes UP, wavelength goes DOWN. (Many short, choppy waves)

• When frequency goes DOWN, wavelength goes UP. (Few long, rolling waves)

Imagine shaking a long rope. If you shake it very fast (high frequency), you create many small waves (short wavelength). If you shake it slowly (low frequency), you create long, lazy waves (long wavelength).

The Wavelength Formula

This relationship is described by one of the most important formulas in physics:

Speed = Frequency × Wavelength

For electromagnetic waves (like light, Wi-Fi, and radio), the "Speed" is a constant: the speed of light, often represented by the letter c.

So, the formula is: c = f × λ

• c: The speed of light (~300,000,000 meters/second)

• f: Frequency (in Hertz)

• λ (Lambda): Wavelength (in meters)

This formula proves that if frequency (f) increases, wavelength (λ) must decrease for the speed to remain constant.

Practical Example: An FM Radio Station

• A station at 98.1 MHz has a frequency of 98,100,000 Hz.

• Using the formula, we can find its wavelength:
  Wavelength = Speed of Light / Frequency
  Wavelength = 300,000,000 / 98,100,000 ≈ 3.06 meters

• The radio waves carrying the music are about 3 meters long!

Internal Link: To convert the frequency units used in this formula, visit our Frequency Converter.