Wireless

WiFi Channel Planner

Pick a band and channel width, set how many APs you will deploy and get a channel plan with maximum reuse and no overlap. Detects co-channel and overlap interference on the fly. Everything is computed in your browser.

redzilla.cl — wifi

20 MHz channels

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available in the band

Non-overlapping

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at the chosen width

Reuse per AP

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times the plan repeats

Available channels · 20 MHz

non-overlapping DFS (radar) in the plan checked

Channel plan · AP → channel

AP	Channel	Center (MHz)	Type	Notes

How overlapping works

In 2.4 GHz each 20 MHz channel is centered every 5 MHz, so two channels overlap if their difference is less than 5 (|c1 − c2| < 5). That is why the classic plan is 1 / 6 / 11: they are the only three that do not step on each other.

In 5 / 6 GHz the 20 MHz channels do not overlap with each other; overlap appears when you do bonding (40 = 2 contiguous channels, 80 = 4, 160 = 8). Two APs sharing any subchannel interfere. Channels marked DFS must yield to radars (waits and possible channel changes).

Runs locally in your browser · no sign-up · nothing leaves your browser

How it works

The planner models the IEEE 802.11 bands: in 2.4 GHz, channels 1 to 13 with centers every 5 MHz (two channels collide if |c1 − c2| < 5, hence the classic 1/6/11); in 5 GHz, the 20 MHz channels of the UNII-1, UNII-2A and UNII-2C groups (the latter two with DFS) and UNII-3; and in 6 GHz (Wi-Fi 6E) the 59 channels 1, 5, 9… 233. With 40, 80 or 160 MHz widths it bonds contiguous channels (2, 4 or 8 subchannels of 20 MHz) without crossing regulatory groups.

From the band, width and number of APs, it builds the set of mutually non-overlapping channels and assigns APs cyclically: if there are more APs than base channels, it reports the reuse factor (unavoidable co-channel between distant cells). You can also check a specific channel against the plan and see whether it is clean, co-channel or in partial overlap, and which channels require DFS (they must yield to radar).

Example: 8 APs on 5 GHz with 80 MHz channels

Each 80 MHz channel bonds 4 contiguous 20 MHz subchannels within its UNII group.
That yields 6 non-overlapping blocks: 36, 52, 100, 116, 132 and 149 (those in 52–144 are DFS).
With 8 APs and 6 base channels, reuse is ×2: two channels repeat, so those AP pairs should be placed as far apart as possible.

Frequently asked questions

How many WiFi channels do not overlap in 2.4 GHz?

Only three: 1, 6 and 11. Centers are 5 MHz apart but each channel occupies 20 MHz, so any pair closer than 5 channel numbers collides. Using in-between channels like 3 or 8 creates partial overlap, which produces more noise than sharing a channel.

What is a DFS channel and should I use it?

DFS (Dynamic Frequency Selection) applies to 5 GHz channels 52–64 and 100–144, shared with weather and military radars. The AP must listen before transmitting and vacate the channel if it detects radar, which causes waits and occasional channel changes. They are still worth using in dense deployments: they make up most of the available 5 GHz spectrum.

What is the difference between co-channel and overlapping interference?

In co-channel, two APs share exactly the same channel: devices hear each other and take turns via CSMA/CA, so throughput drops but the protocol still works. In partial overlap, channels collide without understanding each other: each network sees the other as noise and retransmissions spike. That is why partial overlap in 2.4 GHz is worse than co-channel.

Should I use 80 or 160 MHz channels?

Wider channels mean more throughput per AP but far fewer non-overlapping channels: in 5 GHz you go from 25 channels at 20 MHz to 6 blocks at 80 MHz and a single block at 160 MHz. In multi-AP deployments 40 MHz (or even 20 MHz in high density) usually performs better; in 6 GHz there is plenty of spectrum for wide channels.

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Disclaimer

We take great care to keep every tool accurate and review it thoroughly; even so, we can't guarantee it is free of errors or take responsibility for how the results are used. We recommend double-checking anything critical.

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