Frequency to Wavelength Conversion

Convert frequency and wavelength with velocity factor

Target Variable

Required Parameters

Frequency

Velocity factor

Waiting for input data...

Ad Placement

Sidebar Adaptive Ad Slot

Quick Answer

Wavelength (λ) = Velocity / Frequency. In a vacuum, velocity is the speed of light (c). In a cable or PCB, waves travel slower, requiring a Velocity Factor (VF) between 0.5 and 0.9.

Documentation

Frequency to Wavelength Calculator

Convert between frequency and wavelength for electromagnetic waves. Essential for antenna design, RF engineering, and optics.

Need period instead of wavelength? Use our Frequency to Period Calculator — T = 1/f with reverse solve.

Formula

wavelength = c / f

Where c = speed of light (299,792,458 m/s) and f = frequency in Hz.

Common References

2.4 GHz WiFi = 12.5 cm wavelength
5 GHz WiFi = 6.0 cm wavelength
900 MHz cellular = 33.3 cm wavelength
FM radio (100 MHz) = 3.0 m wavelength
Visible light (600 THz) = 500 nm wavelength

Related Tools

Reactance Calculator
Trace Impedance Calculator
dBm to Watts Converter

Design Notes

Never assume signals travel at the speed of light over a PCB or through a coaxial cable. For example, standard FR4 PCB material has a VF of roughly 0.45 to 0.55 depending on the trace geometry. This means a 1 GHz signal, which has a 30 cm wavelength in air, will only have a ~15 cm wavelength on your PCB. If you are designing quarter-wave matching stubs or length-matching high speed lines, using the correct velocity factor is critical.

Common Mistakes

1
Using c (300,000 km/s) for calculations inside coax cables. RG-58 coax typically has a VF of 0.66, meaning the wave is 34% slower.
2
Confusing Hz with MHz/GHz resulting in calculation errors off by millions. Always use base SI units or keep track of the scientific notation.
3
Ignoring the effect of dielectric loading. Exposing a trace to air vs encapsulating it in conformal coating changes the local velocity factor.

Engineering Handbox

1. Convert Frequency: 2.4 GHz = 2,400,000,000 Hz 2. Base Wavelength (Air): λ = c / f = 299,792,458 / 2.4e9 = 12.49 cm 3. Apply Velocity Factor: 12.49 cm × 0.66 = 8.24 cm

VerificationThe wavelength inside the RG-58 coax is 8.24 cm. A quarter-wave stub should be ~2.06 cm.

Related Engineering Tools

analog signal