Sales rep attrition: benchmarks and the real capacity cost
Sales rep attrition is the annual rate at which quota-carrying reps leave the team, voluntarily or involuntarily. It quietly removes selling capacity twice: once when the rep leaves, and again while the backfill re-ramps.
Attrition benchmarks
| Metric | Benchmark | Source |
|---|---|---|
| Median annual AE turnover | ~30% (voluntary + involuntary) | The Bridge Group SaaS AE research |
| Average AE tenure | 2.8 years | The Bridge Group SaaS AE research |
| Reps achieving quota | ~43–51% | RepVue Q2 2025 Cloud Sales Index; The Bridge Group |
| Common planning range | 15–25% annual attrition | Optimistic vs. the 30% median — know which side you're on |
The real cost of one departure
The naive view: lose a rep in March, lose 9 months of their capacity. The real sequence is worse, because a departure triggers a chain: notice → open territory → backfill hired (typically 2–4 months later) → backfill ramps (3–6+ months). Worked example at an $800K quota and 70% attainment (a ramped rep = $46,667/month of capacity):
| Phase | Months | Capacity delivered |
|---|---|---|
| Rep leaves end of March | — | — |
| Territory open (backfill search) | April–June | $0 |
| Backfill ramping (5-month curve) | July–November | 20% → 100%, avg 60% |
| Backfill at full productivity | December | 100% |
One March departure ≈ $233K of lost capacity — 5 full rep-months, even though the seat is refilled.
A 10-rep team at the 30% median expects three of these a year.
That's why a “15% attrition” input in a capacity model is doing far more work than it looks like it's doing, and why the free calculator treats attrition as a first-class input rather than a footnote.
Why attrition compounds
In year one, a 15% attrition rate costs roughly half that in capacity (leavers depart throughout the year, so on average you lose half their remaining months). The compounding arrives in year two: territories that cold-started, customer relationships reset, and — per the tenure benchmark — a team that turns over every ~2.8 years is perpetually part-ramped. Teams that model attrition honestly hire ahead of it; teams that don't discover the gap in Q3, after the hiring deadline has passed.
FAQ
What attrition rate should I use in a capacity plan?
Your own trailing rate if you have it. If not: 15% is optimistic, 20–25% is typical, 30% is the published SaaS median. Run your plan at two rates and look at the spread — that spread is your risk.
Does backfilling remove the cost of attrition?
No — it caps it. Even an instant backfill re-pays the full ramp curve. With a realistic 3-month search plus a 5-month ramp, a backfill returns to full productivity 8 months after the departure.
How do I model backfill lag in a spreadsheet?
Track departures by month, seat each backfill after your lag assumption, and apply the ramp curve from the seat date. The QuotaMath Excel model ($9.99) implements exactly this — backfill lag and the cost of open territories are editable inputs.
Last updated July 2026 · Sources: The Bridge Group SaaS AE research (30% median turnover, 2.8-yr tenure, 51% quota achievement) · RepVue Q2 2025 Cloud Sales Index (~43% attainment, n≈47,000)