Estimate the number of people your connection can support at the same time without treating the advertised line rate as fully usable. The calculator removes a capacity reserve, accounts for protocol overhead, and divides the remaining throughput by realistic per-user demand. Use the result for office sizing, event Wi-Fi planning, branch upgrades, or a quick stress-test of a shared internet circuit.
The whole-number result is a planning capacity, not a login limit. It assumes active users have roughly similar average demand and that the entered bandwidth is the bottleneck.
Measure peak-hour traffic when possible. Wi-Fi airtime, upstream limits, application bursts, and ISP congestion can reduce real capacity.
With 500 Mbps, a 20% reserve, 2.5 Mbps per active user, and 12% overhead, usable bandwidth is 400 Mbps and provisioned demand is 2.84 Mbps per user. The planning capacity is 140 concurrent users.
Use the direction that becomes constrained first. For video calls and cloud backups, run the calculation separately for upload and download.
A concurrent user is actively consuming bandwidth during the same planning interval, not merely connected or authenticated.
Headers, encryption, retransmissions, and tunneling consume capacity that is not reflected in application payload demand.
It estimates throughput capacity only. Radio airtime, channel width, interference, and access-point client limits also matter.
A fraction of a user cannot be fully supported at the entered demand, so planning capacity uses the next lower whole number.
| Variable | Meaning |
|---|---|
| Bandwidth | Total link throughput in Mbps |
| Reserve | Capacity intentionally kept unused |
| User demand | Average active-user payload rate |
| Overhead | Non-payload share of provisioned throughput |