The band your Wi-Fi, Bluetooth, wireless mouse and microwave oven all share. Watch the walkthrough, then play with the instruments below it.
2.4 billionwave cycles every second
12.5 cmdistance between crests, about 5 in
2.400–2.4835GHz: the whole band, 83.5 MHz wide
Common mix-up: 2.4 GHz is not between infrared and ultraviolet. It sits far below infrared, in the microwave part of the radio range. Infrared, visible light and UV are all much higher frequencies. Chapter 3 shows exactly where.
0:00 / 1:54
Instrument 1
Spectrum explorer
Drag across the entire electromagnetic spectrum. Every stop is the same kind of wave; only the frequency changes. Watch how wavelength, energy and everyday examples change with it.
Frequency
Wavelength
Compared with 2.4 GHz
Energy per photon
Instrument 2
Wi-Fi channel map
Pick a channel to see how much of the band it covers and which neighbours it collides with. Channels outlined in teal are the classic non-overlapping set.
Side by side
2.4 vs 5 vs 6 GHz
Band
Wavelength
Through walls
Room for data
Best for
2.4 GHz
12.5 cm
Best of the three
3 clean 20 MHz channels; crowded
Range, smart-home devices, IoT, older gear, Bluetooth
5 GHz
~6 cm
Moderate
Many more channels; room for 80 and 160 MHz widths
Fast laptops and phones a room or two away
6 GHz
~5 cm
Weakest
Up to 1,200 MHz of clean spectrum (Wi-Fi 6E and 7)
Highest speed, lowest interference, same room as the router
Cheat sheet
Terms you'll run into
Hertz (Hz)
Cycles per second. kHz is a thousand, MHz a million, GHz a billion.
Wavelength (λ)
Distance between crests. Speed of light ÷ frequency. Higher frequency, shorter wave.
Band
A range of frequencies set aside for a use. "2.4 GHz" is shorthand for 2.400–2.4835 GHz.
ISM
Industrial, Scientific and Medical. Unlicensed bands anyone can use within power limits, which is why Wi-Fi, Bluetooth and ovens share 2.4 GHz.
Channel
A slice of the band one network uses. 2.4 GHz Wi-Fi channels are 5 MHz apart but about 20 MHz wide.
Channel width
How much spectrum one signal occupies. Wider means more data per second, like more lanes on a road.
Attenuation
Signal lost along the way. Walls, water (including people) and distance all attenuate, more so at higher frequencies.
Non-ionizing
Photons too weak to knock electrons off atoms. All radio, including 2.4 GHz, is in this group; it can warm things, which is how ovens work, but it doesn't break chemical bonds.
Keep going
The deep dive: how all of this works
This page is one chapter of a bigger story. Each one below has its own walkthrough and instruments.