2.4 GHz Channel Planner
Plan a 2.4 GHz deployment against the only three non-overlapping channels, and see the co-channel contention it creates.
About 2.4 GHz Channel Planner
The 2.4 GHz band is 83.5 MHz wide, which fits only three 20 MHz channels without overlap, so every extra radio has to share one of them. Because co-channel radios take turns rather than transmitting simultaneously, their airtime demands add up until the channel is fully busy. 2.4 GHz is the band legacy IoT and guest devices land on, and leaving it enabled on every AP is the most common cause of a Wi-Fi network that tests well and performs badly.
Formula
2.4 GHz Channel
radios per channel = 2.4 GHz radios ÷ usable channels; channel utilisation = radios per channel × airtime demanded per radio.
- usableChannels
- 3 with 1/6/11, halved if 40 MHz bonding is enabled
- airtimeDemand
- Share of airtime one radio's clients ask for
Worked example
With the default values below, 2.4 GHz Channel Planner returns Radios Sharing Each Channel of 4.00. Change any input above and every figure here is recalculated in your browser.
Inputs used
- 2.4 GHz radios in the coverage areaaccepts 1–500 radios
- 12 radios
- Non-overlapping channels in your regulatory domainone of 3 — channels 1/6/11 (FCC and most of the world), 4 — channels 1/5/9/13 (ETSI, 13 channels)
- 3 — channels 1/6/11 (FCC and most of the world)
- Using 40 MHz channel bonding
- No
- Airtime demanded per radioaccepts 1–100 %
- 30 %
Results
- Radios Sharing Each Channel
- 4.00
- Usable Channels
- 3
- Co-Channel Neighbours per Radio
- 3.00
- Resulting Channel Utilisation
- 100.0%
- Assessment
- Saturated — reduce 2.4 GHz radios or disable the band on some APs
Step by step
- 1Values used
- 22.4 GHz Channel
- 3Radios Sharing Each Channel= 4.00
- 4Usable Channels= 3
- 5Co-Channel Neighbours per Radio= 3.00
- 6Resulting Channel Utilisation= 100.0
- 7Assessment= Saturated — reduce 2.4 GHz radios or disable the band on some APs
Assumptions and limits
- The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
- Figures are rounded for display to 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
Frequently Asked Questions
How is 2.4 GHz Channel calculated?
radios per channel = 2.4 GHz radios ÷ usable channels; channel utilisation = radios per channel × airtime demanded per radio. The 2.4 GHz band is 83.5 MHz wide, which fits only three 20 MHz channels without overlap, so every extra radio has to share one of them. Because co-channel radios take turns rather than transmitting simultaneously, their airtime demands add up until the channel is fully busy.
Why does 2.4 GHz Channel matter?
2.4 GHz is the band legacy IoT and guest devices land on, and leaving it enabled on every AP is the most common cause of a Wi-Fi network that tests well and performs badly.
What values do I need to enter?
This calculator takes 4 inputs: 2.4 GHz radios in the coverage area, Non-overlapping channels in your regulatory domain, Using 40 MHz channel bonding, Airtime demanded per radio. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.