👥 Call Center Staffing Calculator
Enter your call volume, average handle time, interval, and service-level target, and the Erlang C model returns the agents required — plus the resulting occupancy and average speed of answer.
🧮 Size Your Team with Erlang C
👥 Required staffing (Erlang C)
What is a Call Center Staffing Calculator?
It answers the core workforce-planning question: how many agents do I need? Give it the forecast call volume, the average handle time, the interval, and the service level you promise, and it iterates the Erlang C model upward until it finds the smallest team that meets the target, then reports that team's occupancy and average speed of answer.
It is the inverse of the wait time calculator and shares the same tested Erlang C core. Use it to build a staffing plan interval by interval, to justify a hiring request with hard numbers, or to see how much extra headcount a tighter service-level commitment would cost.
❓ Frequently Asked Questions
How does the staffing calculator find the number of agents?
It runs the Erlang C model repeatedly, starting from the minimum number of agents that keeps the queue stable and adding one agent at a time until the resulting service level meets your target — for example 80% of calls answered within 20 seconds. The first count that clears the target is the required staffing.
What service-level target should I set?
The classic contact-centre standard is 80% of calls answered within 20 seconds, but it varies by industry and channel; sales lines and emergency services aim higher, back-office queues lower. Enter whatever target your operation commits to and the calculator sizes the team to hit it.
What is occupancy and why does it matter?
Occupancy is the share of time agents spend handling calls (offered load ÷ agents). High occupancy looks efficient but leaves no slack, so wait times spike and agents burn out. The calculator reports the occupancy at the recommended headcount so you can check it sits in a sustainable range, typically 70–85%.
How is this different from the wait time calculator?
They share the same Erlang C engine but work in opposite directions. The wait time calculator takes a fixed agent count and tells you the service level; this staffing calculator takes a target service level and tells you the agents needed to reach it.