Calculate aggregate switching bandwidth, uniform port speed or capacity-equivalent ports using Gbps, Mbps or Tbps. Choose transmit-plus-receive accounting (×2) or one direction (×1). This arithmetic does not benchmark a switch.

Uniform port rates only. This bandwidth arithmetic does not verify packet forwarding, uplink bottlenecks or real switch performance.

Related Calculators

Switching Capacity Formula

The basic switching capacity formula is:

SC = PS × PC × DF
  • SC = switching capacity
  • PS = port speed
  • PC = port count
  • DF = duplex factor, usually 2 for full-duplex or 1 for one direction

To calculate port speed:

PS = SC / (PC × DF)
  • PS = port speed
  • SC = switching capacity
  • PC = port count
  • DF = duplex factor

To calculate port count:

PC = SC / (PS × DF)
  • PC = port count
  • SC = switching capacity
  • PS = port speed
  • DF = duplex factor

The calculator converts Mbps, Gbps, and Tbps to a common Gbps base before calculating. Full-duplex switching capacity counts transmit and receive traffic, so the factor is 2. If you only want one direction, use a factor of 1.

Common Port Speeds and Full-Duplex Capacity

Port speed 1 port full-duplex capacity 24 ports full-duplex capacity 48 ports full-duplex capacity
100 Mbps 200 Mbps 4.8 Gbps 9.6 Gbps
1 Gbps 2 Gbps 48 Gbps 96 Gbps
2.5 Gbps 5 Gbps 120 Gbps 240 Gbps
10 Gbps 20 Gbps 480 Gbps 960 Gbps
25 Gbps 50 Gbps 1.2 Tbps 2.4 Tbps

Switching Capacity Unit Conversions

Unit Equivalent in Gbps Example
Mbps 1 Mbps = 0.001 Gbps 1000 Mbps = 1 Gbps
Gbps 1 Gbps = 1 Gbps 48 Gbps = 48 Gbps
Tbps 1 Tbps = 1000 Gbps 1.2 Tbps = 1200 Gbps

Example

If a switch has 48 ports and each port is 1 Gbps, the full-duplex switching capacity is:

SC = 1 × 48 × 2 = 96 Gbps

For 48 ports at 1 Gbps per direction, transmit-plus-receive bandwidth accounting gives 96 Gbps. This bandwidth figure alone does not establish line-rate packet forwarding or remove uplink bottlenecks. Compare the vendor’s accounting convention, forwarding rate and traffic-path limits separately.