Ethernet capacity
Switch port calculator
Count every physical connection and reserve practical room for expansion before selecting a switch size.
Your inputs
Calculated result
24-port switch
14 active connections plus 3 spare ports requires at least 17 ports. A 24-port switch is the next practical size.
Active ports
14
Spare ports planned
3
Minimum target
17
How to use this result
- • Count link-aggregated NAS connections individually.
- • Reserve ports for the router or upstream switch.
- • Port count alone does not guarantee enough PoE ports, PoE wattage, or link speed.
How the calculation works
- Count every physical connection: access points, PoE cameras, wired clients, each NAS link and each uplink to a router or another switch.
- Add spare capacity as a percentage of active connections, rounded up to whole ports.
- Choose the next common switch size (5, 8, 16, 24 or 48 ports) at or above the target.
Worked example
A typical connected home
- 2 access points + 4 cameras + 5 wired clients + 2 NAS links + 1 uplink = 14 active ports
- 20% spare capacity adds 3 ports
- Target: 17 ports
14 active connections plus 3 spare ports requires at least 17 ports. A 24-port switch is the next practical size.
Common questions
Does a NAS with link aggregation need two ports?
Yes. Each aggregated link uses its own switch port, and the switch must support LACP (802.3ad) for aggregation to work.
Do I need to count the port that connects to my router?
Yes. The uplink to the router or upstream switch occupies a port like any other device.
Is port count the only thing to check?
No. Confirm how many ports provide PoE, which PoE standard they support, the total PoE budget, and whether the port speeds (1, 2.5 or 10 GbE) match your access points and NAS.