Frequency to Wavelength Converter – Instant RF & Light Calculator

📡 Frequency to Wavelength Converter

Convert any frequency to wavelength instantly — supports Hz, kHz, MHz, GHz & THz in both metric and imperial units

Quick Presets
🔧 Input Settings
✅ Conversion Results
📡 Common Frequencies & Wavelengths
300 m
AM Radio (1 MHz)
3 m
FM Radio (100 MHz)
12.5 cm
WiFi 2.4 GHz
6 cm
WiFi 5 GHz
10.7 mm
5G 28 GHz
19 cm
GPS L1 1575 MHz
650 nm
Red Light (460 THz)
400 nm
Violet Light (750 THz)
📋 Frequency Band Reference Table
Band Name Abbreviation Frequency Range Wavelength Range Typical Use
Extremely Low FreqELF3 – 30 Hz10,000 – 100,000 kmSubmarine comms
Super Low FreqSLF30 – 300 Hz1,000 – 10,000 kmAC power grid
Very Low FreqVLF3 – 30 kHz10 – 100 kmNavigation, time signals
Low FreqLF30 – 300 kHz1 – 10 kmAM longwave radio
Medium FreqMF300 kHz – 3 MHz100 m – 1 kmAM broadcast radio
High FreqHF3 – 30 MHz10 – 100 mShortwave, amateur radio
Very High FreqVHF30 – 300 MHz1 – 10 mFM radio, TV, aviation
Ultra High FreqUHF300 MHz – 3 GHz10 cm – 1 mTV, WiFi, LTE, GPS
Super High FreqSHF3 – 30 GHz1 – 10 cmRadar, satellite, WiFi 5G
Extremely High FreqEHF30 – 300 GHz1 – 10 mm5G mmWave, security
InfraredIR300 GHz – 430 THz700 nm – 1 mmRemote controls, thermal
Visible LightVIS430 – 750 THz400 – 700 nmHuman vision
🌊 Wavelength by Medium (at 2.4 GHz)
Medium Refractive Index / VF Wave Speed Wavelength at 2.4 GHz Wavelength at 5 GHz
Vacuum / Free Spacen = 1.000299,792,458 m/s124.9 mm60.0 mm
Airn ≈ 1.0003≈ 299,702,547 m/s124.9 mm59.9 mm
Freshwatern = 1.333224,900,644 m/s93.7 mm45.0 mm
Glassn = 1.500199,861,639 m/s83.3 mm40.0 mm
Optical Fibern = 1.468204,218,296 m/s85.1 mm40.8 mm
Siliconn = 3.50085,655,000 m/s35.7 mm17.1 mm
Coax CableVF = 0.66197,863,022 m/s82.4 mm39.6 mm
Twisted PairVF = 0.64191,867,173 m/s79.9 mm38.4 mm
📏 Wavelength Unit Conversion Reference
Meters (m) Centimeters (cm) Millimeters (mm) Micrometers (µm) Nanometers (nm) Feet (ft) Inches (in)
1 m100 cm1,000 mm1,000,000 µm1,000,000,000 nm3.281 ft39.37 in
0.1 m10 cm100 mm100,000 µm100,000,000 nm0.328 ft3.937 in
0.01 m1 cm10 mm10,000 µm10,000,000 nm0.0328 ft0.394 in
0.001 m0.1 cm1 mm1,000 µm1,000,000 nm0.00328 ft0.0394 in
0.000001 m0.0001 cm0.001 mm1 µm1,000 nm0.00000328 ft0.0000394 in
0.000000001 m0.0000001 cm0.000001 mm0.001 µm1 nm3.28e–9 ft3.94e–8 in
💡 Core Formula: Wavelength (λ) = Speed of Light (c) ÷ Frequency (f). In free space, c = 299,792,458 m/s. For other media, divide c by the refractive index (n): λ = c ÷ (n × f). For transmission lines, use velocity factor (VF): λ = (c × VF) ÷ f.
💡 Half-Wave Antenna Tip: A half-wave dipole antenna should be λ/2 in length. For WiFi at 2.4 GHz, the ideal dipole length is approximately 6.24 cm (2.46 in). For 5 GHz WiFi, it is approximately 3.0 cm (1.18 in). Always account for the velocity factor of your antenna material.

Whether you need to convert between wavelengths and frequencies? A wavelength-frequency converter can be your helper. Those programs allow you to switch between both without stopping your work taking the wavelength of an electromagnetic wave and giving its frequency value; or the other way.

The best part? Almost all are freely available online as calculators, so anyone that needs them can use them.

How to Convert Wavelength and Frequency

The convert itself is not hard because when one understands the basics. One simply rearranges the equation that ties wavelength, frequency and the speed of a wave. Enter two known values, solve for the third and done.

Because the speed of light is fixed, one can even prepare a whole table for the relation between wavelengths and frequencies, which is very handy.

How to find wavelength? Divide the speed of light by the frequency. Light travels at around 300 millions of metres each second, to be more exact, around 299 792 458 metres each second.

Wavelength is the distance between two peaks of a wave, measured in metres. Frequency on the other hand measures in cycles each second. When one has those definitions, the math goes natrually.

Many converters allow change between various units, depending on your work. This is useful, because different areas use different labels. Here is a sample of a free tool, that supports conversions for more than 35 units of frequency and wavelengths.

We talk about hertz, exahertz, petahertz, terahertz, so everything from radio waves too microwaves.

Besides the general converters, there are also dedicated versions. Radio frequency engineers use separate tools for wireless signal work and frequency planning in communications. Workers with lasers have their own calculators, that switch between laser wavelength and frequency in both directions.

There are even niche tools, that estimate wavelength of a signal specially in dielectric materials, as involved with cables and RF-boards.

Some calculators go beyond the basic conversion. One of them counts coherent length directly from a linear beam, which is handy for optical work. Another takes conversions of ITU-based allocations, when one goes from frequency to wavelength.

And for optical systems, there are tools, that handle optical wavelengths and frequency conversions directly.

One must know about another concept, the wave number, that one calculates, it is frequency divided by the speed of light or the other way, one divided by wavelength. There is also photon energy, that mixes frequencies with the Planck constant and the basic formula. This matters especially for short wavelengths and high-energy radiation, like x-rays and gamma rays.

To convert delta frequency into delta wavelength, one needs another formula. Delta frequency equals the speed of light times delta wavelength, all divided by the square of wavelength. So, if you have a delta wavelength of 0.4 nanometres and your wavelength is 1550 nanometres, the deltafrequency results in around 50 gigahertz.

The math always checks out.

Frequency to Wavelength Converter – Instant RF & Light Calculator

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