Free Erlang C Staffing Calculator
Calculate exact agent headcount to meet SLAs instantly. Free interactive Erlang C staffing calculator for call centers — no signup required.
What this tool does
Use the Erlang C queueing formula to calculate the exact number of agents needed to meet a service-level target for a given ticket or call volume. Accounts for random arrivals, queueing, and real-world shrinkage.
Inputs
- Ticket or call volume per hour
- Average handle time (AHT) in minutes
- Target service level (percentage of contacts answered)
- Target answer time (seconds)
- Shrinkage percentage (breaks, training, meetings, time off)
Outputs
- Required scheduled agents (after shrinkage)
- Required productive agents (Erlang C raw)
- Predicted service level achieved
- Predicted occupancy percentage
- Predicted average speed of answer
Frequently asked questions
What is the Erlang C formula?
Erlang C is a mathematical model used in workforce management to determine the exact number of agents needed to handle a predicted volume of tickets or calls while meeting a specific Service Level target. It accounts for random arrival patterns and queueing theory.
What is Average Handle Time (AHT)?
Average Handle Time (AHT) is the total average duration of a support interaction. This includes the time spent reading the ticket, investigating the issue, writing the response, and any post-interaction wrap-up work.
What does Shrinkage mean in staffing?
Shrinkage is the percentage of time that agents are paid for but not available to handle tickets. This includes breaks, meetings, training, vacation, and sick leave. Factoring in shrinkage ensures your schedule reflects actual available hours, not just total headcount.
Is this staffing calculator free?
Yes. Our Erlang C Staffing Calculator runs entirely in your browser with no signup and no credit card required. Your metrics stay local to your device unless you request a PDF report.