What Is Shrinkage in a Call Center? Definition, Formula, and Examples

If you manage a call center, you’ve probably heard the term shrinkage thrown around. But what does it really mean, why does it matter so much, and how do you calculate it?

Let’s break it down in plain English.

What Is Shrinkage in a Call Center?

Shrinkage is the percentage of time that agents are unavailable to handle customer interactions. You will hear it categorized into planned or unplanned shrinkage.

Think of it like this: just because someone is on the schedule doesn’t mean they’re always on the phones. Breaks, meetings, training sessions, absenteeism — all of these eat into your available staffing.

Even the best-planned schedule will fall apart if shrinkage isn’t factored in.

Common Causes of Shrinkage

Shrinkage typically comes from two main buckets:

Planned Shrinkage
- Breaks and lunches
- Training
- Team meetings
- Coaching sessions
Unplanned Shrinkage
- Sick calls
- Absenteeism
- Unexpected technical issues
- Ad hoc offline tasks

Every contact center experiences both — the only difference is whether you’ve planned for it or not.

The Call Center Shrinkage Formula

The standard way to calculate shrinkage is:

Shrinkage % = (Time not available ÷ Total time scheduled) × 100

Example:

An agent is scheduled for 8 hours (480 minutes).
They spend 60 minutes in breaks, 30 minutes in training, and miss 30 minutes due to lateness.
Total unavailable time = 120 minutes.

Shrinkage = (120 ÷ 480) × 100 = 25%

That means you’re only getting 75% of their time as actual “productive” handling time.

Why Shrinkage Matters

Let’s say your call center needs 10 agents available at all times to hit service goals.

If you don’t account for 30% shrinkage, you’ll schedule 10 people, but only 7 will actually be available. Suddenly, you’re understaffed, SLAs slip, and customer experience suffers.

This is why workforce planners layer shrinkage on top of staffing calculations. If your calculations say you need 10 people, and shrinkage is 30%, you really need ~13 scheduled.

Typical Shrinkage Benchmarks

Small to mid-sized centers: 25–35%
Enterprise centers with more offline programs: 35–45%
Centers with strict adherence and fewer meetings: closer to 20–25%

The key isn’t hitting a “magic number” — it’s measuring your reality and planning around it.

Shrinkage in Small Contact Centers

Here’s the kicker: shrinkage hurts small teams more.

In a 100-person center, losing 3 agents to shrinkage barely makes a dent.
In a 10-person center, losing 3 agents means you just lost nearly a third of your workforce.

That’s why small and lean teams can’t afford to ignore shrinkage — the margin for error is razor thin.

How Spark Queue Handles Shrinkage

This is exactly the problem we designed Spark Queue to solve.

Instead of forcing you to manually tack on “extra heads” in Excel, Spark Queue layers shrinkage into staffing automatically. You can see the true number of agents you need per interval, accounting for reality — not just theory.

For small and mid-sized contact centers, this means:

More accurate schedules
Fewer surprise understaffing moments
SLAs that stay green

Because let’s face it: shrinkage is always there. The question is whether you plan for it or let it wreck your day.