Estimate the number of simultaneous users a network link can support without consuming its full rated capacity. The calculator converts total bandwidth into a practical usable pool, holds back a reserve for bursts and overhead, and divides the remainder by each active user’s expected throughput. Use the spare-capacity result to see whether the design still has room for traffic variation.
The main result is the largest whole number of active users that fits inside the planned bandwidth pool. It is a capacity estimate, not a guarantee: protocol behavior, uneven user demand, and another bottleneck can lower observed performance.
Treat per-user bandwidth as concurrent sustained demand. If you only know a file size, first convert it into a required transfer rate for the desired completion time.
For a 1,000 Mbps link, 5 Mbps per active user, 75% planned utilization, and a 10% reserve, usable bandwidth is 675 Mbps. The result is 135 concurrent users, with 0 Mbps left after allocating whole-user demand.
Use the direction that constrains the workload. For two-way traffic, run each direction separately and use the lower capacity.
A partial user cannot be admitted while preserving the selected per-user bandwidth, so the safe whole-user result is rounded down.
No. The utilization setting limits normal loading, while the reserve removes another share of that planned pool for bursts and overhead.
Use bandwidth per simultaneously active user. Registered or idle users do not consume the same sustained transfer capacity.
Run a heavy-user scenario or use a weighted average based on the expected mix, then validate it with traffic measurements.
| Variable | Meaning | Unit |
|---|---|---|
| B | Rated bottleneck capacity | Mbps |
| u | Planned utilization | % |
| r | Burst reserve | % |
| p | Demand per active user | Mbps |