NAS, RAID and Backup Storage

SSD endurance calculator.

SSD endurance is the total data the drive is rated to take: years = TBW x 1,000 / daily writes in GB / 365. A 1 TB drive rated 600 TBW written at 100 GB a day reaches its rating in 6,000 days, about 16.4 years. Enter a TBW or DWPD rating and your daily writes. Runs in your browser; nothing is sent or stored.

Your SSD

Rating type Both appear on SSD datasheets.

Drive capacity (GB) For example 1000 for a 1 TB drive.

Rating (TBW or DWPD, matching the type above) For TBW enter terabytes, for DWPD enter drive writes per day.

Warranty length (years) Required for DWPD. For TBW it is used to compare with the warranty; enter 0 to skip.

Average data written per day (GB) Host writes per day. Your OS or SMART tool can report total data written so you can measure this.

Endurance

Fill the form and press Calculate.

Worked example

A 1 TB (1,000 GB) SSD rated 600 TBW with 100 GB written a day: 600 TBW x 1,000 / 100 = 6,000 days = 16.4 years, which is 0.10 drive writes per day. Over a 5 year warranty you would write 182.5 TB, well inside the rating. For a DWPD rating: a 1.92 TB drive rated 1 DWPD for 5 years is 1.92 x 1 x 365 x 5 = 3,504 TBW; at 500 GB a day that lasts 7,008 days = 19.2 years.

How it works

Datasheets give endurance as TBW (total terabytes that can be written within the warranty period) or DWPD (how many times the full capacity can be written per day within the warranty period). They convert: TBW = capacity (TB) x DWPD x 365 x warranty years. Years of life = TBW x 1,000 / daily GB written / 365.

The rating is a manufacturer figure, not a prediction of failure: a drive can wear out earlier or later, and the warranty usually ends on whichever limit comes first, years or TBW. Check your own drive's datasheet for its terms. To measure your real daily writes, read the total data written from your drive's SMART data twice, a few days apart.

Estimates only. RAID is not a backup: it keeps an array running through a drive failure but does not protect against deletion, malware, fire or theft. Real arrays and drives vary, so use this for planning and check your own drive datasheets.

Sources and basis (opened 2026-10-08):

Solid-state drive (Wikipedia): Endurance is typically listed as n DWPD or m TBW; its Samsung 970 EVO 1 TB example is rated 600 TBW. It also summarizes JEDEC reliability metrics: TBW is the total terabytes written within the warranty period and DWPD is the number of times the full capacity can be written per day within the warranty period. We did not open the JEDEC standard itself.

FAQ

How do I calculate SSD lifespan from TBW?

Divide the TBW rating, in GB, by your daily writes in GB and by 365. For 600 TBW and 100 GB a day that is 600,000 / 100 / 365 = 16.4 years.

How do I convert DWPD to TBW?

Multiply capacity in TB by DWPD, by 365 and by the warranty years. A 1.92 TB drive at 1 DWPD for 5 years is 3,504 TBW.

Will my SSD die when it reaches its TBW?

Not necessarily. TBW is a rating tied to the warranty, not an exact failure point. Some drives last past it, but you should plan on replacing the drive and keep backups.

How much data do I write per day?

Most home users write far less than the rating suggests. Read the total data written from SMART data, wait a few days, read it again and divide the difference by the days.

Does a NAS cache need higher endurance?

Often yes, because a read-write cache can see heavy writes. Enter the cache drive capacity, rating and expected daily writes to check.