Short answer: Apple’s published router recommendations are to keep 2.4 GHz at 20 MHz and to set 5 GHz and 6 GHz to Auto (or all widths). In our view that suits most homes: narrowing a 5 GHz channel is worth trying only if connections are unreliable in a crowded area, and 320 MHz only matters if you have Wi-Fi 7 devices that use 6 GHz.
What channel width changes
A channel is the slice of a band your router transmits on, and its width is how big that slice is. Each step up doubles it: 40 MHz is two 20 MHz channels side by side, 80 MHz is four. More width lets a single connection carry more data, so the top speed goes up.
The cost is interference. Apple puts it plainly: wider channels are faster, but they are more susceptible to interference and more likely to interfere with other devices. A wider channel also takes up more of the band, so the band holds fewer of them side by side. How many channels each band has is covered in 2.4 GHz vs 5 GHz vs 6 GHz.
Which widths each Wi-Fi generation supports
| Wi-Fi generation | Channel widths |
|---|---|
| Wi-Fi 5 (802.11ac) wave 1 | 20, 40, 80 MHz |
| Wi-Fi 5 (802.11ac) wave 2 | adds 160 MHz |
| Wi-Fi 6 and 6E (802.11ax) | 20, 40, 80, 160 MHz |
| Wi-Fi 7 (802.11be) | adds 320 MHz |
Intel’s protocol reference lists 20 to 80 MHz for the first wave of Wi-Fi 5, 160 MHz as a second-wave addition, and 20 to 160 MHz for Wi-Fi 6. The Wi-Fi Alliance lists 160 MHz among Wi-Fi 6 features, and says Wi-Fi 7’s 320 MHz channels are available in the 6 GHz band. Which bands each generation uses is explained in our Wi-Fi standards guide, along with the theoretical speed of each width.
A connection can only use a width that both ends support. Intel’s Wi-Fi 6E AX210 laptop adapter, for example, tops out at 160 MHz, so a 320 MHz setting on the router does nothing for it. To see what your own devices can use, check which Wi-Fi your device supports.
The setting to use on each band
2.4 GHz: 20 MHz. Apple recommends it because it avoids performance and reliability problems near other Wi-Fi networks and 2.4 GHz devices, including Bluetooth. Our Wi-Fi channels guide covers which 20 MHz channel to pick.
5 GHz and 6 GHz: Auto. Apple recommends Auto or all widths here and notes that interference is less of a concern in these bands. On Auto, the router chooses among the widths it supports. Apple doesn’t give specific widths for these bands.
Width settings are usually in the router’s wireless or Wi-Fi settings, sometimes on an advanced or professional page; see how to log in to your router.
320 MHz: Wi-Fi 7 on 6 GHz
320 MHz needs Wi-Fi 7 on both ends and the 6 GHz band. The Wi-Fi Alliance rates these channels at twice the throughput of Wi-Fi 6. There are few of them, and how many depends on the country: in a Juniper webinar, a speaker notes three in the US and another notes one in Europe.
Apple’s recommendations don’t mention 320 MHz, and whether a router’s Auto setting includes it varies by router, so check its settings page. Turning it on only helps Wi-Fi 7 devices that connect on 6 GHz; it does nothing for older devices. What else Wi-Fi 7 changes is in Wi-Fi 7 explained.