Calculators
Contact center shift calculator
Enter the number of agents you need on the line, your contact center's hours (hours per day and days per week), shift length, and how many shifts one person works per week. You get shifts per day, people per shift, and headcount adjusted for breaks, PTO, and sick leave.
Calculator
How many people to schedule
The values are too large for Erlang A mode: reduce the number of calls, the target time or the patience.
The calculator shows average headcount. If volume swings a lot during the day, work out agents on the line for each hour and build your schedule around the peaks.
Shifts per day = hours of operation per day ÷ shift length, rounded up
People per shift = agents on the line ÷ (1 − shrinkage), rounded up
Headcount = people per shift × shifts per day × days of operation ÷ shifts per week per person, rounded up
Shift overlap = shifts per day × shift length − hours of operation per dayMethod
How the calculator works
The number of agents on the line comes from the Erlang calculator, which works it out from call volume, handle time, and your target service level. The Plan shifts button under its results brings the agent count and shrinkage over here. Both calculators work out people per shift the same way; the shift calculator adds a schedule for the whole week.
First, the calculator works out how many shifts you need per day: hours of operation divided by shift length, rounded up. If shifts don't divide the day evenly, they overlap – during those hours, two shifts are on the line at once.
Next, how many people to put on each shift. Some staff are always on break, on PTO, or out sick, so you schedule more people than you need on the line: the agent count is divided by the share of time people actually work.
Headcount is the number of shifts you need to cover in a week divided by the number of shifts one person works. That way, every shift on the schedule is fully staffed.
Result
How to read the result
- Headcount – how many people you need to cover every shift in the week, accounting for breaks, PTO, and sick leave.
- Shifts per day – how many shifts it takes to cover your hours of operation.
- People per shift – how many people to schedule on each shift so that, after absences, you have the right number of agents on the line.
- Shift overlap – how many hours a day two shifts work at once. During those hours you have twice as many people on the line: put the overlap on your peak hours, or if you have no peaks, try a different shift length.
Example
Example
A contact center is open 12 hours a day, 7 days a week, needs 10 agents on the line, runs 8-hour shifts, and each person works 5 shifts a week, with 30% shrinkage. You need 2 shifts a day of 15 people each, overlapping 4 hours a day. That's 15 × 2 × 7 = 210 shifts a week, and one person covers 5 – so you need a headcount of 42. With 12-hour shifts, one shift a day and a headcount of 21 would do, but each person would have to work 60 hours a week.
More
Where to use it
Glossary
Terms on this page
- Shrinkage
- Paid time when agents are off the line: breaks, training, sick leave. Learn more →
- Service level (SL)
- The share of calls answered within a set time – for example, 80% in 20 seconds. Learn more →
- Workforce management (WFM)
- Workload forecasts and agent shift schedules. Learn more →