Decades to generations, if it's kept dry. The iron itself basically doesn't wear out.
The short answer
A cast iron pan has no realistic expiration date under normal use. Pans from the early 1900s are still in daily use in plenty of kitchens today, often cooking better than the day they were bought thanks to decades of built-up seasoning. What limits a pan’s life isn’t age — it’s neglect.
What actually shortens a pan’s life
| Risk | Effect |
|---|---|
| Prolonged rust left untreated | Pits the surface over years — still fixable, just more work |
| A hard crack from a severe drop | The one genuinely unfixable failure, and it’s rare |
| Warping from extreme, uneven heat | Uncommon with normal stovetop use; more a risk with thin cookware |
| Neglected seasoning | Cosmetic and functional setback, not permanent damage |
Why it outlasts almost everything else in a kitchen
Cast iron is thick, solid metal with no coating to wear off, no nonstick layer to scratch away, and no moving parts. The seasoning on top is the only thing that degrades with misuse, and that’s rebuildable indefinitely — see the seasoning guide and rust removal guide for how.
In practice: a cast iron pan bought today is a reasonable candidate to be passed down, not replaced. The main thing standing between “lasts forever” and “rusted beyond easy repair” is just keeping it dry between uses.