Work out how many agents you need, and why.
Free calculators for contact centre planning that show their working, and plain-English guides to the maths behind them. No sign-up, no ads, no spreadsheet.
Five-minute handle time, 80% in 20 seconds, 85% occupancy ceiling, 30% shrinkage. Erlang C in every half hour, then shrinkage, then a week at 90% roster efficiency. Change any of it in the planner.
Calculators
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Erlang C calculator
How many agents you need on the phones to hit a service level target, with the occupancy and ASA that implies.
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Week planner and FTE calculator
From a daily, weekly or monthly volume to a staffing curve, agent-hours and FTE.
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Staffing requirement calculator
From volume and handle time through Erlang C, an occupancy ceiling and shrinkage to the agents to put on the roster.
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Shrinkage calculator
Total, external and internal shrinkage from leave, sickness, training and breaks, and the agents to schedule.
Interval calculators
Planning tools
- Email and ticket staffing calculator
- Schedule efficiency calculator
- Forecast accuracy calculator
- Attrition rate and cost calculator
- Leave allowance calculator
- AI deflection ROI calculator
- Minimum staffing calculator for 24/7 cover
- Cost per contact calculator
- FTE to headcount converter
- Absence rate and Bradford factor calculator
- First contact resolution and repeat contact calculator
- Staffing shortfall and overtime calculator
- Outbound campaign staffing calculator
- Seasonality and monthly forecast calculator
- Intraday reforecast calculator
Guides
All guides-
How much cross-training is enough?
One second skill for everyone captures most of what full flexibility offers, but only if the skills join the queues into a chain. Simulated, not guessed.
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How to forecast with no history: a new centre, product or campaign
When there is no data to extrapolate: forecast from a driver, a contact rate, a shape and a handle time, staff the range not the point, and replace it fast.
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How to staff for a spike, a campaign or a product launch
A known uplift on an existing line: size it in contacts, give it a shape, see what it does to the requirement, and choose between overtime, borrowing and delay.
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Is your call target reasonable? The maths behind calls per day and occupancy
For agents and team leaders: what a daily call target, an occupancy figure and time between calls mean, and how to check whether yours is achievable at your handle time.
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Staffing a service desk or back office to an SLA in hours or days
Tickets and cases do not queue like calls. How to staff work with a turnaround SLA: throughput first, then the backlog the deadline allows, then the peak that breaks it.
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WFM analyst interview questions, with worked answers
Twelve questions a workforce planning interview actually asks, from Erlang C to intraday, each with the answer, the number, and the calculator that proves it.
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Where to put breaks and lunches so the curve stays covered
Breaks are shrinkage inside the interval. How to see what they do to the requirement, stagger them into the troughs, and check a break plan with the fit calculator.
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How to calculate Erlang C staffing for a contact centre
A step-by-step worked example of the Erlang C calculation: from contact volume and handle time to the agents you need for an 80/20 service level.
Pebble WFM, the app
The people behind this site make Pebble WFM, workforce management for contact centres. It forecasts demand, works out how many people each interval needs, builds and publishes the roster, and lets agents swap shifts and ask for time off against it. Agents can connect their Google Calendar so they aren't rostered into their appointments.