Call Center Staffing (Erlang C) & Service Level Calculator
Calculate agent staffing needs to meet service level agreements. Enter values for instant results with step-by-step formulas.
Worked Examples
Example 1: Standard SLA
Problem:100 calls/hr, 5 min AHT. Target 80/20.
Solution:Traffic = 8.33 Erlangs. Need ~11-12 agents.
Result:12 Agents
Example 2: High Volume
Problem:500 calls/hr, 3 min AHT. Target 90/10.
Solution:Traffic = 25 Erlangs. Need ~30 agents.
Result:30 Agents
Frequently Asked Questions
What is Erlang C?
A mathematical formula derived by A.K. Erlang in 1917 to determine the number of telephone circuits needed. In call centers, it calculates staffing based on queuing theory (assuming calls wait in a queue).
How do I lower staffing needs?
Reduce AHT (better training/tools) or Reduce Volume (Deflection/Self-Serve).