Agents needed for 100 calls an hour
100 calls an hour with a five-minute handle time is 8.3 erlangs of work and needs 12 agents on the phones to answer 80 per cent within 20 seconds, at 69% occupancy. The table runs the same Erlang C calculation across handle times and two common targets; every row opens the calculator with those inputs so you can change anything else.
| Handle time | Erlangs | Agents for 80/20 | Occupancy at 80/20 | Agents for 90/60 | To schedule at 30% shrinkage |
|---|---|---|---|---|---|
| 180 s | 5.0 | 8 | 63% | 8 | 12 |
| 240 s | 6.7 | 10 | 67% | 10 | 15 |
| 300 s | 8.3 | 12 | 69% | 12 | 18 |
| 360 s | 10.0 | 14 | 71% | 14 | 20 |
| 420 s | 11.7 | 16 | 73% | 16 | 23 |
| 480 s | 13.3 | 18 | 74% | 18 | 26 |
| 600 s | 16.7 | 22 | 76% | 22 | 32 |
Click a handle time to open the calculator with that row's inputs.
Assumptions
- Calls arrive at random across a 60-minute interval; Erlang C with no abandonment.
- Agents shown are on the phones for the whole hour. The last column divides by 0.7 and rounds up.
- No occupancy ceiling is applied; small volumes come out under 85%, large ones above it, and the staffing requirement calculator adds the ceiling.
Frequently asked questions
- Why does 100 calls an hour need more agents than the erlangs?
- Erlangs are the average number of calls in progress. Calls bunch, so agents above that average are needed to keep queues short; the gap is the price of the service level target, and it shrinks as a share of the total at higher volumes.
- Is this per hour or per day?
- Per hour, for one hour that looks like this. A day has quiet and busy hours; the week planner spreads a daily or monthly total across intervals and adds the hours up.
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