Wavelength & Frequency Converter
Convert frequency to wavelength and back, including velocity factor for cable and PCB.
Example: 2.4 GHz has a wavelength of 124.9 mm in vacuum / air.
Formula
λ = c × velocity factor / fWorked example
2.4 GHz has a wavelength of 124.9 mm in vacuum / air.
λ = c × VF / f
299.8 Mm/s × 1 / 2.4 GHz
124.9 mm
Frequently asked questions
How do I convert frequency to wavelength?
Divide the speed of light by the frequency: λ = c / f. At 2.4 GHz that is about 125 mm in free space. In a cable or on a PCB the signal travels slower, so multiply by the velocity factor.
What is velocity factor?
How fast a signal travels relative to light in a vacuum. RG-58 coax is about 0.66, FR4 microstrip roughly 0.5. It matters because any dimension derived from wavelength — antenna elements, stub lengths, matching sections — shrinks by the same factor.
When does a PCB trace become a transmission line?
Around a tenth of a wavelength. Shorter than that and it behaves as a plain wire; longer and reflections from impedance mismatches start to matter. At 2.4 GHz on FR4 that threshold is only about 6 mm, which is why RF layout is so unforgiving.
Related tools
Antenna Length Calculator
Quarter-wave, half-wave and dipole lengths for any frequency, with presets for 433, 868, 915 and 2400 MHz and the ham bands.
RF & Signals
Free Space Path Loss Calculator
Link budget and estimated range for LoRa, WiFi and BLE from TX power, gains and sensitivity.
RF & Signals
PCB Trace Impedance Calculator
Characteristic impedance for microstrip, stripline and differential pairs — the geometry you need for USB, Ethernet and HDMI.
Power & Wiring
LC Resonant Frequency Calculator
Resonant frequency, Q factor and bandwidth for LC tank circuits.
Circuits
LoRa Airtime Calculator
Time-on-air from spreading factor, bandwidth and coding rate, with EU and US duty-cycle legality checks.
RF & Signals
Nyquist & Sampling Rate Calculator
Minimum sample rate, alias frequencies and anti-alias filter requirements for a given signal.
RF & Signals