SSD Lifetime Calculator
Estimate remaining SSD lifespan from its rated TBW endurance, cumulative writes so far, and current daily write rate.
Inputs
Manufacturer's Total Bytes Written rating, e.g. from the drive's datasheet
Cumulative host writes so far, from smartctl Total_LBAs_Written or similar
Estimated Remaining Lifespan
26.91years
Endurance Consumed
20.00%
Estimated Remaining Lifespan
9,830days
Status
Healthy — well within rated endurance
Step by step
Values used
Rated Endurance (TBW) = 600 TB; Total Written So Far = 120 TB; Current Daily Write Rate = 50 GB/day
Remaining lifespan in days
remaining_days = (rated_TBW − total_written) / daily_writes
Estimated Remaining Lifespan
= 26.91 years
Endurance Consumed
= 20.00
Estimated Remaining Lifespan
= 9,830 days
Status
= Healthy — well within rated endurance
How it works
SSD manufacturers rate endurance in Total Bytes Written (TBW) — the total data volume the drive is warrantied to absorb before flash cell wear meaningfully increases failure risk. Subtracting cumulative writes so far from the rated TBW gives the remaining write budget, and dividing that by the current daily write rate projects how many more days of use remain at that rate. This is a linear projection assuming a steady write rate; workloads with growing write volume (more logging, larger databases, heavier caching) will exhaust the remaining budget faster than this estimate suggests.
Formula
Remaining lifespan in days
remaining_days = (rated_TBW − total_written) / daily_writes
- W_{rated}
- manufacturer rated TBW
- W_{used}
- cumulative writes so far
- w
- current daily write rate
Frequently Asked Questions
How do I find total writes so far on a Linux system?
Run `smartctl -a /dev/sdX` (or /dev/nvme0n1 for NVMe drives) and look for 'Total_LBAs_Written' (SATA SSDs, multiply by the logical block size, usually 512 bytes) or the 'Data Units Written' field (NVMe, each unit is 512,000 bytes) to get cumulative host writes.
Does exceeding the rated TBW mean the SSD will immediately fail?
Not necessarily — TBW is a conservative warranty threshold, and many SSDs continue operating well beyond their rated endurance, though the risk of uncorrectable errors and eventual failure increases as flash cells wear out, so treat exceeding TBW as an increasing risk rather than a hard failure point.
Why might my actual daily write rate be higher than what I observe at the application layer?
Write amplification means the SSD controller often writes more data internally than the host requested, due to wear-leveling, garbage collection and how flash pages must be erased in larger blocks before rewriting — actual NAND writes measured by the drive's own SMART data can exceed host-level writes by a meaningful factor depending on workload pattern and drive overprovisioning.