Count the non-overlapping 5 GHz channels available at your chosen width with or without DFS, and check the reuse it allows.
Excluding DFS leaves only UNII-1 (36–48) and UNII-3 (149–165), which is nine 20 MHz channels and no 160 MHz channel at all. Adding the UNII-2 and UNII-2e radar bands roughly triples the count, at the cost of radar-detection channel changes. Channel reuse is what determines whether adjacent APs cooperate or compete, and avoiding DFS to dodge radar events is exactly what starves a dense floor of spectrum.
5 GHz Channel
channels = usable 5 GHz spectrum ÷ channel width, counted separately for the DFS and non-DFS sets; radios per channel = radios ÷ channels.
channels = usable 5 GHz spectrum ÷ channel width, counted separately for the DFS and non-DFS sets; radios per channel = radios ÷ channels. Excluding DFS leaves only UNII-1 (36–48) and UNII-3 (149–165), which is nine 20 MHz channels and no 160 MHz channel at all. Adding the UNII-2 and UNII-2e radar bands roughly triples the count, at the cost of radar-detection channel changes.
Channel reuse is what determines whether adjacent APs cooperate or compete, and avoiding DFS to dodge radar events is exactly what starves a dense floor of spectrum.
This calculator takes 3 inputs: Channel width, DFS (UNII-2 / UNII-2e) channels permitted, 5 GHz radios in the coverage area. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.