Work out port density requirement instantly with clear inputs, formula shown and shareable results.
Port count planning must reserve capacity twice: a growth allowance on the device count, and a few ports per switch kept free for troubleshooting, temporary connections and infrastructure such as access points and cameras. Without the second reservation, a fully populated switch forces a new switch for a single additional device.
Port planning
ports needed = devices x (1 + growth); usable per switch = ports - reserved; switches = ceil(ports needed / usable per switch)
Stack ports are usually dedicated and do not consume access ports, but check the model — some use SFP+ slots that would otherwise be uplinks.
Enough to cover the equipment refresh cycle, typically five years. Twenty to thirty percent is common, more where headcount is growing.