What formula does this calculator use?

It uses c = λf, where c = 299,792,458 m/s (speed of light in a vacuum), λ is wavelength in meters, and f is frequency in hertz. Rearranged: λ = c / f and f = c / λ.

Does this apply to radio waves, microwaves, and light?

Yes. All electromagnetic waves travel at the speed of light in a vacuum, so the same formula applies across the entire EM spectrum — from extremely low frequency (ELF) radio waves to visible light and beyond.

Why is the speed of light used rather than a different propagation speed?

This calculator assumes free-space (vacuum) propagation. In a medium like a dielectric cable or fiber, the phase velocity is lower by a factor of 1/√εr. For antenna design in air, free-space values are a very close approximation.

What is the wavelength of a 2.4 GHz Wi-Fi signal?

299,792,458 / 2,400,000,000 ≈ 0.1249 m, or about 12.5 cm. This is why 2.4 GHz antennas are typically a few centimeters long (quarter-wave ≈ 3.1 cm).

How accurate are the results?

Results use the exact NIST value of c (299,792,458 m/s) and JavaScript double-precision floating point, giving accuracy to at least 10 significant figures — well beyond any practical engineering need.

Frequency Wavelength Calculator

Name: Frequency Wavelength Calculator
Availability: InStock
Author: Nham Vu

Enter a frequency or wavelength to instantly convert between the two using the speed of light formula c = λf.

Convert Frequency / Wavelength

Frequency

Wavelength

Result

Enter a value and click Calculate.

Copied!

EM Spectrum Band Reference

Band	Abbreviation	Frequency Range	Wavelength Range	Typical Use
Extremely Low Frequency	ELF	3 – 30 Hz	10,000 – 100,000 km	Submarine comms
Very Low Frequency	VLF	3 – 30 kHz	10 – 100 km	Navigation, time signals
Low Frequency	LF	30 – 300 kHz	1 – 10 km	AM longwave, RFID
Medium Frequency	MF	300 kHz – 3 MHz	100 m – 1 km	AM broadcast
High Frequency	HF	3 – 30 MHz	10 – 100 m	Shortwave, amateur radio
Very High Frequency	VHF	30 – 300 MHz	1 – 10 m	FM radio, TV, aviation
Ultra High Frequency	UHF	300 MHz – 3 GHz	10 cm – 1 m	Wi-Fi, LTE, Bluetooth, GPS
Super High Frequency	SHF	3 – 30 GHz	1 – 10 cm	Radar, 5G mmWave, satellite
Extremely High Frequency	EHF	30 – 300 GHz	1 – 10 mm	mmWave imaging, 5G
Infrared / Visible / UV	IR/VIS/UV	300 GHz – 3 PHz	100 nm – 1 mm	Optics, fiber, lasers

Summary

Enter a frequency or wavelength to instantly convert between the two using the speed of light formula c = λf.

How it works

Select the direction of conversion: frequency to wavelength, or wavelength to frequency.
Enter the known value and choose its unit (Hz, kHz, MHz, GHz for frequency; mm, cm, m, km for wavelength).
Click Calculate or press Enter — the result appears immediately.
Use the Copy button to copy the result to your clipboard.
Reference the band table below to identify the electromagnetic spectrum band for your frequency.

Use cases

Calculate the wavelength of a radio, microwave, or optical signal given its frequency.
Determine the resonant frequency of an antenna given its physical length.
Identify which RF band (LF, HF, VHF, UHF, SHF) a given frequency falls into.
Design antenna elements where physical size equals a fraction of a wavelength.
Verify textbook problems and homework for physics or RF engineering courses.
Convert between spectral representations in optics and photonics.

Frequently Asked Questions

Last updated: 2026-07-01 · Reviewed by Nham Vu