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TBW and DWPD conversion table for SSD endurance ratings

How to convert between TBW (terabytes written) and DWPD (drive writes per day) for an SSD, with a worked table of 60 rows: six capacities from 0.25 to 8 TB, warranty periods of 3 and 5 years, and DWPD ratings of 0.1, 0.3, 1, 3 and 10. The formulas are TBW = DWPD x capacity x 365 x years and DWPD = TBW / (capacity x 365 x years). Pure arithmetic from the public definitions, with no measured data and no product ratings. For example, 1 TB at 1 DWPD over 5 years is 1,825 TBW, and 600 TBW on a 1 TB drive over 5 years is 0.33 DWPD.

Download CSV60 rows · 6 columns · CSV

File /data/datasets/ssd-endurance-tbw-dwpd-calc.csv · JSON metadata · Chart (SVG) · TBW glossary entry · DWPD glossary entry · All datasets

Scope and definitions

Scope: a conversion table, not a survey. It lists no product and no vendor rating. DWPD is the number of times the full capacity of the drive can be written per day over the warranty period, and TBW is the total number of terabytes that can be written over that period. These are the definitions given in the Wikipedia article on solid-state drives, which also notes that manufacturers give endurance as either n DWPD or m TBW.

Formulas

TBW = DWPD × capacity (TB) × 365 × warranty years
DWPD = TBW ÷ (capacity (TB) × 365 × warranty years)
host writes per day (GB) = DWPD × capacity (TB) × 1000
full-drive P/E cycles at write amplification 1 = TBW ÷ capacity (TB), the same as DWPD × 365 × warranty years

Terabytes are decimal (1 TB = 10¹² bytes) and a year is 365 days. The table is a grid of 6 capacities (0.25, 0.5, 1, 2, 4, 8 TB), 2 warranty periods (3 and 5 years) and 5 DWPD values (0.1, 0.3, 1, 3, 10): 60 rows. The build recomputes every cell from its formula and fails on a mismatch, and it checks that converting each TBW back to DWPD returns the DWPD of the row.

Worked examples

A 1 TB drive rated 1 DWPD for 5 years: 1 × 1 × 365 × 5 = 1,825 TBW, or 1,000 GB of host writes per day. The same rating on a 4 TB drive is 7,300 TBW, and over 3 years on the 1 TB drive it is 1,095 TBW.
The other direction: a 1 TB drive rated 600 TBW over 5 years is 600 ÷ (1 × 365 × 5) = 0.33 DWPD. The 600 TBW figure is an arithmetic example, not a product. With write amplification 1 it is 600 full-drive P/E cycles, the example the Wikipedia article gives for 1 TB and 600 TBW.
The same TBW means a lower DWPD on a larger drive or over a longer warranty: DWPD is TBW spread over capacity and days.

Chart

Log-log plot of TBW against capacity from 0.25 to 8 TB for DWPD ratings of 0.1 to 10 over a five-year warranty. At 1 TB the lines run from 182.5 TBW at 0.1 DWPD to 18250 TBW at 10 DWPD. — Five-year rows only. Every point is a CSV cell.

Limits

These are ratings arithmetic, not measured endurance. A real drive can wear out earlier or later than its rating, and the table says nothing about any product.
Vendors tie a rating to a workload and a warranty period. The same drive can carry a different TBW under a different workload, so two ratings are comparable only when workload and period match.
The P/E column assumes write amplification 1. Real write amplification is above 1, so the P/E cycles the flash actually sees are higher than that column, and the column is a count of host full-drive writes.
Capacity is decimal and the year has 365 days. A vendor that uses another convention, or counts a leap year, will get slightly different numbers.

Table

Same 60 rows as the CSV.
Capacity (TB)	Warranty (years)	DWPD	TBW	Host writes (GB/day)	P/E cycles at WAF 1
0.25	3	0.1	27.375	25	109.5
0.5	3	0.1	54.75	50	109.5
1	3	0.1	109.5	100	109.5
2	3	0.1	219	200	109.5
4	3	0.1	438	400	109.5
8	3	0.1	876	800	109.5
0.25	3	0.3	82.125	75	328.5
0.5	3	0.3	164.25	150	328.5
1	3	0.3	328.5	300	328.5
2	3	0.3	657	600	328.5
4	3	0.3	1,314	1,200	328.5
8	3	0.3	2,628	2,400	328.5
0.25	3	1	273.75	250	1,095
0.5	3	1	547.5	500	1,095
1	3	1	1,095	1,000	1,095
2	3	1	2,190	2,000	1,095
4	3	1	4,380	4,000	1,095
8	3	1	8,760	8,000	1,095
0.25	3	3	821.25	750	3,285
0.5	3	3	1,642.5	1,500	3,285
1	3	3	3,285	3,000	3,285
2	3	3	6,570	6,000	3,285
4	3	3	13,140	12,000	3,285
8	3	3	26,280	24,000	3,285
0.25	3	10	2,737.5	2,500	10,950
0.5	3	10	5,475	5,000	10,950
1	3	10	10,950	10,000	10,950
2	3	10	21,900	20,000	10,950
4	3	10	43,800	40,000	10,950
8	3	10	87,600	80,000	10,950
0.25	5	0.1	45.625	25	182.5
0.5	5	0.1	91.25	50	182.5
1	5	0.1	182.5	100	182.5
2	5	0.1	365	200	182.5
4	5	0.1	730	400	182.5
8	5	0.1	1,460	800	182.5
0.25	5	0.3	136.875	75	547.5
0.5	5	0.3	273.75	150	547.5
1	5	0.3	547.5	300	547.5
2	5	0.3	1,095	600	547.5
4	5	0.3	2,190	1,200	547.5
8	5	0.3	4,380	2,400	547.5
0.25	5	1	456.25	250	1,825
0.5	5	1	912.5	500	1,825
1	5	1	1,825	1,000	1,825
2	5	1	3,650	2,000	1,825
4	5	1	7,300	4,000	1,825
8	5	1	14,600	8,000	1,825
0.25	5	3	1,368.75	750	5,475
0.5	5	3	2,737.5	1,500	5,475
1	5	3	5,475	3,000	5,475
2	5	3	10,950	6,000	5,475
4	5	3	21,900	12,000	5,475
8	5	3	43,800	24,000	5,475
0.25	5	10	4,562.5	2,500	18,250
0.5	5	10	9,125	5,000	18,250
1	5	10	18,250	10,000	18,250
2	5	10	36,500	20,000	18,250
4	5	10	73,000	40,000	18,250
8	5	10	146,000	80,000	18,250

Columns

capacity_tb (number): Drive capacity in decimal terabytes (1 TB = 10^12 bytes).
warranty_years (integer): Warranty period in years, each of 365 days.
dwpd (number): Drive writes per day: full-capacity writes per day allowed for the warranty period.
tbw (number): Terabytes written over the warranty period: dwpd * capacity_tb * 365 * warranty_years. Exact decimal arithmetic.
host_writes_gb_per_day (number): dwpd * capacity_tb * 1000, gigabytes of host writes per day.
pe_cycles_at_waf_1 (number): tbw / capacity_tb = dwpd * 365 * warranty_years: full-drive program/erase cycles used if write amplification is 1. Real drives have write amplification above 1, so this is a count of host full-drive writes.

License

The table is arithmetic computed here from the public definitions of TBW and DWPD. No third-party data or specification text is copied and no product rating is listed. Reuse is fine with attribution to this site.

Wikipedia reuse terms · Definitions source

Sources

Solid-state drive, Wikipedia: endurance section defining TBW and DWPD (accessed 2026-10-11)
Write amplification, Wikipedia: program/erase cycles and write amplification (accessed 2026-10-11)