{
  "slug": "ssd-endurance-tbw-dwpd-calc",
  "title": "TBW and DWPD conversion table for SSD endurance ratings",
  "kind": "dataset",
  "summary": "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.",
  "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.",
  "licenseUrl": "https://en.wikipedia.org/wiki/Wikipedia:Copyrights",
  "sourceUrl": "https://en.wikipedia.org/wiki/Solid-state_drive",
  "accessed": "2026-10-10",
  "rowCount": 60,
  "columns": [
    {
      "name": "capacity_tb",
      "type": "number",
      "description": "Drive capacity in decimal terabytes (1 TB = 10^12 bytes)."
    },
    {
      "name": "warranty_years",
      "type": "integer",
      "description": "Warranty period in years, each of 365 days."
    },
    {
      "name": "dwpd",
      "type": "number",
      "description": "Drive writes per day: full-capacity writes per day allowed for the warranty period."
    },
    {
      "name": "tbw",
      "type": "number",
      "description": "Terabytes written over the warranty period: dwpd * capacity_tb * 365 * warranty_years. Exact decimal arithmetic."
    },
    {
      "name": "host_writes_gb_per_day",
      "type": "number",
      "description": "dwpd * capacity_tb * 1000, gigabytes of host writes per day."
    },
    {
      "name": "pe_cycles_at_waf_1",
      "type": "number",
      "description": "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."
    }
  ],
  "downloadPath": "/data/datasets/ssd-endurance-tbw-dwpd-calc.csv",
  "chartPath": "/data/datasets/ssd-endurance-tbw-dwpd-calc.svg",
  "citations": [
    {
      "id": "wp-ssd",
      "title": "Solid-state drive, Wikipedia: endurance section defining TBW and DWPD",
      "url": "https://en.wikipedia.org/wiki/Solid-state_drive",
      "accessed": "2026-10-11"
    },
    {
      "id": "wp-wa",
      "title": "Write amplification, Wikipedia: program/erase cycles and write amplification",
      "url": "https://en.wikipedia.org/wiki/Write_amplification",
      "accessed": "2026-10-11"
    }
  ]
}