PostMicroTools
Reference + calculator
LTO archive calculator
How many LTO tapes you need to archive a project, across copies, and how long it takes to write. Capacities are native — compression doesn't help already-compressed video.
LTO generations
| Gen | Native capacity | Native speed | Reads back to |
|---|---|---|---|
| LTO-9 | 18 TB | ~400 MB/s | LTO-8 |
| LTO-8 | 12 TB | ~360 MB/s | LTO-7 |
| LTO-7 | 6 TB | ~300 MB/s | LTO-5/6 |
| LTO-6 | 2.5 TB | ~160 MB/s | LTO-4/5 |
| LTO-5 | 1.5 TB | ~140 MB/s | LTO-3/4 |
Why native capacity, not compressed?
Vendors quote a 2.5:1 "compressed" figure, but video is already compressed, so you effectively get the native capacity. Plan with native numbers.
Best practice
Use LTFS for self-describing, cross-platform restores. Keep 2 tape copies + 1 off-site (3-2-1), verify with checksums after writing, and migrate tapes every ~7–10 years or two LTO generations.