Workload inputs
Add up to eight work types, then set your planning assumptions.
Fill this in to see the hiring gap.
Informational: clearing daily volume is what keeps the turnaround promise.
Productive FTE the workload demands, before shrinkage.
FTE required plus 25% shrinkage, the number to fund.
| Work type | Workload (hrs) | FTE |
|---|---|---|
| Emails | 800 | 6.64 |
| Claims | 750 | 6.22 |
Save or share these results
Take a snapshot of the exact inputs and outputs on screen.
Get the full Excel/VBA version
The full Excel/VBA version with live formulas, RTM tracking, and dashboards is free for now.
Results are estimates for planning purposes only and should not replace professional workforce management judgment.
Back office work does not queue the way calls do: an email waits in a backlog, not on a line, and nobody abandons it. So instead of Erlang models, this calculator uses a clean workload conversion: how many hours of work arrive each month, and how many productive hours one person actually delivers.
Step by step
- Workload hours per work type = (monthly volume × handle time in minutes) ÷ 60.
- Productive hours per FTE = working days × shift hours × productive % × utilisation cap. What one person can really give to this work in a month.
- FTE per work type = workload hours ÷ productive hours per FTE. The total is the sum across all work types.
- Headcount to hire = total FTE ÷ (1 − shrinkage). Adds back the paid hours lost to leave, sickness and training.
Why the utilisation cap matters
Nobody spends every productive minute on the work queue. People answer questions, wait on systems, and switch between tasks. Capping utilisation at 85 to 90 percent keeps the plan honest; planning at 100 percent is the most common reason back office teams fall behind their turnaround promise.
Using it well
- Keep work types separate when their handle times differ a lot; one blended average hides the real requirement.
- Re-run monthly against actual volumes and handle times.
- For the voice side of the operation, use the Capacity Planning Calculator and the Erlang C Calculator.
Frequently asked questions
What counts as a work type?
Any repeatable item with a measurable monthly volume and handle time: emails, claims, applications, refunds, case reviews. Add up to eight.
What is the utilisation cap?
The share of productive time you expect people to spend on this work. Cap it below 100 percent to leave room for questions, system issues and interruptions.
Why is the shrinkage-adjusted FTE higher?
Leave, sickness and training remove paid hours, so you need to hire more people than the raw workload suggests to deliver the same productive hours.
How does the SLA turnaround note fit in?
It is informational only. In back office work, a turnaround promise in days is met by clearing each day's incoming volume, which is exactly what the FTE figure covers.
Related reading: the KPI benchmarks WFM teams should track and the shrinkage formula mistake that breaks service level.
More tools
See all toolsService Level Recovery Calculator
Behind on service level mid-month? Get the volume-weighted SL you need for the rest of the period, and see instantly if the target is already unreachable.
Open calculatorErlang C Staffing Calculator
Turn call volume, AHT and service level targets into required agents, occupancy, ASA and shrinkage-adjusted headcount.
Open calculatorErlang A Calculator
Staffing with abandonment built in: when callers give up and hang up, Erlang A sizes the team more honestly than Erlang C.
Open calculator