101 Wi-Fi channels — and why it is 1, 6 and 11
Channel numbers and frequencies are tied by a formula: on 2.4 GHz the centre is 2407 plus five times the number, and the signal spreads 22 MHz around it.
A channel is a range, not a point
On 2.4 GHz the numbers sit 5 MHz apart while each signal occupies 22 MHz. Neighbours therefore overlap, and only channels five apart — 1, 6 and 11 — clear each other.
The channels that clear each other
These are not copied from a chart — they are picked by comparing the ranges. Channel 14 is the fourth such slot, usable only in Japan.
Browse by band
2.4 GHz reaches far and passes walls but crowds; 5 GHz has many clean channels; 6 GHz has more still, yet a single wall costs it dearly.
2.4 GHz band
5 GHz band
6 GHz band
Channels shared with radar
Channels 52 to 144 on 5 GHz share their band with weather and military radar. A router that detects radar must vacate the channel, so the link can drop for a moment or move on its own.
How to read this
- On 2.4 GHz the centre is 2407 + number × 5; only channel 14 breaks the rule at 2484.
- 5 GHz is 5000 + number × 5, and 6 GHz is 5950 + number × 5.
- A 2.4 GHz signal occupies 22 MHz, so channels must sit five apart to clear each other.
- Bonding to 40 MHz uses two neighbouring channels, leaving fewer places to hide.
Which channels are legal depends on the country. 12 and 13 are allowed in Korea, Europe and Japan but not in the US; 14 is Japan-only and legacy-only; and 6 GHz is still closed in some countries.
Frequently asked questions
Q. Why 1, 6 and 11 on 2.4 GHz?
The numbers are 5 MHz apart but each signal spans 22 MHz, so channels must be five apart to avoid overlapping. 1, 6 and 11 are the three slots that fit; channel 14, used only in Japan, is a fourth.
Q. Should I leave the channel on auto?
Auto is fine for most homes. Pin a channel only if the router keeps hopping among crowded neighbours, or if things slow down at predictable times of day.
Q. Why does my 5 GHz channel change by itself?
If you are on 52–144, that is DFS: when radar is detected the router must vacate the channel. Moving to 149 or above avoids it.
Q. Does 40 or 80 MHz make it faster?
Each transmission carries more, but there is also more room to collide. On a crowded 2.4 GHz band, 20 MHz is usually steadier.
Q. What is different about 6 GHz?
Far more channels and much less crowding, but walls hurt it badly. Both router and device need Wi-Fi 6E or newer, and some countries have not opened the band.