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RayRF | Free RF calculators

Wavelength Calculator (Frequency to Wavelength, Free Space)

Convert frequency to free-space wavelength. lambda_0 = c / f. Returns wavelength, half-wave, and quarter-wave lengths in millimetres and inches. Starting point for any antenna or feed length.

Free-Space Wavelength Calculator

Convert frequency to wavelength in vacuum (or air). lambda_0 = c/f. The starting point for any antenna or feed length.

Units
Length
Frequency

Inputs

GHz
λ₀ = 122.364 mmv = c (vacuum)
Free-space wavelength lambda_0
Wavelength lambda_0
122.364mm
4817.49 mil

More

lambda_0 / 2 (half-wave dipole)61.182 mm
lambda_0 / 4 (monopole)30.591 mm
lambda_0 (inches)4.817 in

Analytical calculation

Free-space wavelength
In vacuum (or air to within 0.03%) the wavelength is c divided by f.

Frequently asked

What's the wavelength of WiFi 2.4 GHz?

At the 2.45 GHz band centre, lambda_0 = 12.24 cm. A quarter-wave whip (lambda_0/4) is about 30.6 mm; a full half-wave dipole is about 61 mm tip-to-tip, with each arm about 30.6 mm. At the band edges (2.412 vs 2.484 GHz) lambda_0 shifts by about 1 mm.

References

Closed-form is just the start.

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