In Jain cosmology, the life span in the 7 naraks (hells) is commonly taught as:

1. 1st Narak — Ratnaprabha: 10,000 years
2. 2nd Narak — Sharkarprabha: 100,000 years
3. 3rd Narak — Valukaprabha: 1,000,000 years
4. 4th Narak — Pankaprabha: 10,000,000 years
5. 5th Narak — Dhumaprabha: 100,000,000 years
6. 6th Narak — Tamahprabha: 1,000,000,000 years
7. 7th Narak — Mahatamahprabha: 10,000,000,000 years

These are the maximum life spans usually described in Jain texts, and each lower narak has a longer stay than the one above it.

If you want, I can also give the full table of all 14 Jain lokas or the conditions for birth in each narak.