Email list decay calculator
Or since the list was built, if it never was.
Presets model the share of people leaving their employer each year from BLS median job tenure, January 2026.
Type your own to override the preset.
Measure your own rate from a re-verified sample
Re-verify a random sample of contacts that were valid on a known date and enter what you found. This is the only rate that describes your list.
- Estimated gone stale
- 1,560
- Share of the list
- 15.6%
- Estimated still current
- 8,440
- Yearly rate used
- 15.6%
At 15.6% a year (the BLS-tenure model for all us workers), about 1,560 of 10,000 contacts have probably moved on in 12 months: 1 − (1 − 0.156)^(12/12).
| After | Stale | Share |
|---|---|---|
| 3 months | 415 | 4.2% |
| 6 months | 813 | 8.1% |
| 12 months | 1,560 | 15.6% |
| 18 months | 2,246 | 22.5% |
| 24 months | 2,877 | 28.8% |
| 36 months | 3,988 | 39.9% |
Not every leaver bounces: companies keep deleted mailboxes for weeks or turn them into shared inboxes, so some stale addresses still accept mail. And some addresses die without anyone leaving, after a rebrand or domain change.
Next step
About 1,560 stale contacts is an estimate. A verification run gives you the real number.
The model can't tell you which contacts are gone. A mailbox check marks every address valid, invalid or risky, so you can remove the dead ones before they bounce; 10,000 contacts fit in the $19 one-time pack (10,000 emails).
Verify the list