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Calcimator

Switch Port Density Calculator

Calculate access, distribution, and core switch count from endpoint count, port requirements, and uplink oversubscription.

Inputs

%
Mbps
Mbps

Results

Access Switches

6

Total Switches

7

Oversubscription Ratio

0.8:1

Distribution Switches1
Core Switches0
Total Usable Ports264
Spare Ports64
Port Utilization75.8 %
Rack Units (1U each)7 RU
Total Ports Installed288
How to Use This Calculator
  1. Enter Total Endpoints, Ports per Switch, and Uplink Ports per Switch.
  2. Set Spare Port Capacity, Access Port Speed, and Uplink Speed.
  3. Review Access Switches, Total Switches, and Oversubscription Ratio (:1).
  4. Use Distribution Switches and Core Switches to inform your decision.
  5. Use the chart to visualize the results and explore different scenarios by adjusting inputs.

How the result changes with Ports per Switch

Ports per SwitchAccess SwitchesTotal SwitchesOversubscription Ratio
1719240.3:1
39780.7:1
65451.3:1
87341.7:1

What each input means

Total Endpoints
Total network endpoints (PCs, phones, printers, APs, cameras, etc.)
Ports per Switch
Total ports per access switch (8, 24, or 48 common)
Uplink Ports per Switch
Ports reserved for uplinks on each access switch
Spare Port Capacity
Additional port capacity for future growth
Access Port Speed
Speed of access layer ports (100/1000/2500/5000/10000)
Uplink Speed
Speed of uplink ports (1G/10G/25G/40G/100G)

How this is calculated

Formula

Switches = ⌈Endpoints × (1 + Spare%) / (Ports - Uplinks)⌉

Worked example, using the default values

  1. Identify Input Parameters
    4 parameters
    Total Endpoints = 200, Ports per Switch = 48, Uplink Ports per Switch = 4, Spare Port Capacity = 20 = 6 input(s) provided
  2. Calculate Access Switches
    Access Switches
    6 = 6
  3. Calculate Total Switches
    Total Switches
    7 = 7
  4. Calculate Oversubscription Ratio
    Oversubscription Ratio
    0.8 = 0.8
  5. Calculate Distribution Switches
    Distribution Switches
    1 = 1
  6. Calculate Core Switches
    Core Switches
    0 = 0

Engine last updated . Checked against 3 independently-derived tests — how we verify calculators.

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