Below is a comparison of the most common Wi-Fi standards and channels available for use in the United States.
|Standard||Frequencies||Max PHY Rate||Bandwidth|
|5 GHz||14 Gbps||20 MHz, 40 MHz, 80 MHz, 80+80 MHz, 160 MHz|
|801.11ac Wave 2 |
|5 GHz||3.47 Gbps||20 MHz, 40 MHz, 80 MHz, 80+80 MHz, 160 MHz|
|5 GHz||1.3 Gbps||20 MHz, 40 MHz, 80 MHz, 160 MHz|
|2.4 GHz, 5 GHz||600 Mbps||20 MHz, 40 MHz|
|2.4 GHz||54 Mbps||20 MHz|
|5 GHz||54 Mbps||20 MHz|
|2.4 GHz||11 Mbps||20 MHz|
Note that the maximum speed/throughput/“bandwidth” specified by device manufacturers almost always represents that device's overall transmission capability, not the internet speed you can expect on a connected device. See this article for more information.
There are eleven 20 MHz-wide and two 40 MHz-wide channels in the 2.4 GHz band. Note that the only “set” of non-overlapping channels are 20 MHz-wide channels 1, 6, and 11:
Higher bandwidths allow for faster speeds, but at the expense of additional opportunities for interference. This is because wider channels use more frequencies, meaning there is a greater chance there may be Wi-Fi or other devices sharing the channel.
Smaller bandwidths are slower but allow for greater device density.
Hardware manufacturers might have “interesting” ways of selecting channels. For example, let's say you wanted to set a UniFi AP to the first available 80 MHz channel. Technically, this would be channel 42. However, UniFi only allows you to select 20 MHz channels. Therefore, you would choose any of the 20 MHz channels within that 80 MHz range (36, 40, 44, or 48) and UniFi would actually set the AP to the correct 80 MHz channel (42).