FTE & budget builder

Budget season needs one number first: how many people, and what do they cost? This tool turns a weekly contact volume into a required full-time-equivalent headcount and an annual staffing cost — an order-of-magnitude figure to anchor the conversation before you build it interval by interval.

Contacts per week

AHT (seconds)

Open hours / week

SL target (% in s)

… seconds

Max occupancy (%)

Shrinkage (%)

Peak uplift (%)

Paid hours / FTE / week

Cost / FTE / year (£)

—

Required FTE
(rostered headcount)

—

Annual staffing
cost

—

Implied cost
per contact

—

Avg agents
on the phones

How the number is built

This is a budgeting estimate, not a roster. It staffs the average interval and adds a flat peak uplift, because a year’s budget doesn’t need interval precision. For the real requirement — which is driven by your busiest intervals, not your average — build the day with the intraday profile builder and pressure-test it with the sensitivity tool.

Why average-plus-uplift, not just average

Staff an average day and you will be short, because contacts don’t arrive evenly — the peaks need more agents than the mean, and Erlang doesn’t let you bank the quiet intervals against the busy ones. The peak uplift is a rough allowance for that unevenness: a flatter operation needs little, a spiky retail or sales line needs more. Treat the default of 15% as a placeholder and replace it with the gap between your real peak-driven requirement and this average figure once you’ve built a profile. Everything else — shrinkage, occupancy, paid hours — you should set from your own measured numbers, not the defaults here.

Maths: Erlang C for the average interval, then grossed for shrinkage and converted to FTE on your paid-hours figure. See the Capacity Planning paper and the capacity-plan template for the month-by-month version.