Home / RF Electronics / RF Wavelength

RF Wavelength Calculator

Calculate RF wavelength, frequency, propagation speed and antenna wavelength fractions.

RF Wave
One complete cycle represents one wavelength
STEP 1

What do you want to calculate?

Wavelength Calculate wavelength from frequency
Frequency Calculate frequency from wavelength
Propagation Speed Calculate wave speed
Quarter-Wave Length Calculate λ/4 antenna length
Half-Wave Length Calculate λ/2 antenna length
STEP 2

Enter the values you know

Enter the RF signal frequency.
Wavelength in free space or the selected medium.
For free space, use approximately 299,792,458 m/s.
Result

RF Wavelength Formula

λ = v ÷ f

λ is wavelength, v is propagation speed and f is frequency.

Speed of Light

For a radio wave traveling through free space, the propagation speed is approximately 299,792,458 m/s.

Example

Consider an RF signal operating at 100 MHz in free space.

λ = 299,792,458 ÷ 100,000,000

The wavelength is approximately 2.998 meters.

Quarter-Wave Antenna

L = λ ÷ 4

A quarter-wave antenna has a physical length based on approximately one quarter of the wavelength.

Half-Wave Antenna

L = λ ÷ 2

Common RF Frequencies

  • 433 MHz
  • 868 MHz
  • 915 MHz
  • 1.2 GHz
  • 2.4 GHz
  • 5.8 GHz
  • 10 GHz

RF and Antenna Design

Wavelength is important when designing antennas, transmission lines, RF layouts and microwave circuits.

The physical length of an antenna can differ from the simple wavelength calculation because of conductor geometry, surrounding materials, dielectric effects and the antenna design.