{
  "id": "dimensional-weight",
  "version": "faec5b98600c",
  "status": "published",
  "name": "Dimensional Weight Calculator",
  "question": "What is the dimensional weight?",
  "summary": "Works out a package’s dimensional (volumetric) weight from its length, width and height and the carrier’s divisor, and the billable weight: the larger of the dimensional and actual weights.",
  "category": "logistics",
  "subcategory": "shipping",
  "url": "https://www.acalculator.org/logistics/dimensional-weight-calculator",
  "markdown": "https://www.acalculator.org/logistics/dimensional-weight-calculator.md",
  "kind": "function",
  "method": "Dimensional weight = L × W × H ÷ divisor (in³ per lb, or cm³ per kg), each side first rounded as chosen; rounded up to the next whole lb or kg. Billable weight = the larger of that and the actual weight rounded up.",
  "assumptions": [
    "Carriers set their own divisors and rounding rules, and change them. Check the carrier’s current rules for your account.",
    "Some services charge dimensional weight only above a size (USPS: over 1 cubic foot, 1,728 in³). The page always shows it.",
    "The steps are exact on the numbers as typed; only the final roundings are shown."
  ],
  "inputs": {
    "$schema": "https://json-schema.org/draft/2020-12/schema",
    "type": "object",
    "properties": {
      "sys": {
        "title": "Divisor units",
        "description": "Inches and pounds (a divisor in cubic inches per pound) or centimetres and kilograms (cm³ per kg).",
        "type": "string",
        "enum": [
          "us",
          "metric"
        ]
      },
      "l": {
        "title": "Length",
        "description": "The package’s length, measured at its longest point.",
        "type": [
          "number",
          "string"
        ],
        "x-quantity": "length",
        "minimum": 0.001,
        "maximum": 30
      },
      "w": {
        "title": "Width",
        "description": "The package’s width, measured at its longest point.",
        "type": [
          "number",
          "string"
        ],
        "x-quantity": "length",
        "minimum": 0.001,
        "maximum": 30
      },
      "h": {
        "title": "Height",
        "description": "The package’s height, measured at its longest point.",
        "type": [
          "number",
          "string"
        ],
        "x-quantity": "length",
        "minimum": 0.001,
        "maximum": 30
      },
      "r": {
        "title": "Round each side",
        "description": "How the carrier rounds each measurement before multiplying: to the nearest whole inch or centimetre, up to the next whole one, or not at all.",
        "type": "string",
        "enum": [
          "nearest",
          "up",
          "none"
        ]
      },
      "div": {
        "title": "Divisor (in³ per lb)",
        "description": "The carrier’s dimensional divisor in cubic inches per pound.",
        "type": "number",
        "minimum": 1,
        "maximum": 10000
      },
      "divm": {
        "title": "Divisor (cm³ per kg)",
        "description": "The carrier’s dimensional divisor in cubic centimetres per kilogram.",
        "type": "number",
        "minimum": 100,
        "maximum": 100000
      },
      "wt": {
        "title": "Actual weight",
        "description": "What the package weighs on a scale. Leave it empty to see the dimensional weight alone.",
        "type": [
          "number",
          "string"
        ],
        "x-quantity": "mass",
        "minimum": 0.000001,
        "maximum": 100000
      }
    }
  },
  "outputs": {
    "result": {
      "label": "Billable weight",
      "description": "The weight the carrier charges for: the larger of the dimensional and actual weights, each rounded up to the next whole pound or kilogram.",
      "format": "text"
    },
    "dimWeight": {
      "label": "Dimensional weight (lb or kg)",
      "description": "Length × width × height ÷ divisor, before rounding up, in pounds or kilograms by the divisor units.",
      "format": "number"
    },
    "dimRounded": {
      "label": "Dimensional weight, rounded up",
      "description": "The dimensional weight rounded up to the next whole pound or kilogram.",
      "format": "integer"
    },
    "billable": {
      "label": "Billable weight (lb or kg)",
      "description": "The larger of the rounded dimensional weight and the rounded actual weight.",
      "format": "integer"
    },
    "volume": {
      "label": "Volume (in³ or cm³)",
      "description": "The product of the three rounded sides, in cubic inches or cubic centimetres.",
      "format": "number"
    }
  },
  "defaultAnswer": {
    "inputs": {
      "sys": "us",
      "l": "12 in",
      "w": "12 in",
      "h": "12 in",
      "r": "nearest",
      "div": 139,
      "divm": 5000
    },
    "outputs": {
      "result": "13 lb",
      "dimWeight": 12.431654676258994,
      "dimRounded": 13,
      "billable": 13,
      "volume": 1728
    },
    "text": "The billable weight is 13 lb; the dimensional weight is 12.43."
  },
  "examples": [
    {
      "given": {
        "sys": "us",
        "l": 0.30479999999999996,
        "w": 0.30479999999999996,
        "h": 0.30479999999999996,
        "r": "nearest",
        "div": 139
      },
      "expect": {
        "dimWeight": 12.431654676258994,
        "dimRounded": 13,
        "billable": 13,
        "volume": 1728,
        "result": "13 lb"
      },
      "source": "FedEx, \"What is dimensional weight?\" (L × W × H in inches, each rounded to the nearest whole inch, ÷ 139), https://www.fedex.com/en-us/shipping/packaging/what-is-dimensional-weight.html (retrieved 2026-10-05); hand calculation in content.mdx: 1,728 ÷ 139 = 12.43, up to 13 lb"
    },
    {
      "given": {
        "sys": "us",
        "l": 0.30479999999999996,
        "w": 0.30479999999999996,
        "h": 0.30479999999999996,
        "r": "nearest",
        "div": 166,
        "wt": 2.2679618500000003
      },
      "expect": {
        "dimWeight": 10.409638554216867,
        "dimRounded": 11,
        "billable": 11,
        "result": "11 lb, by size"
      },
      "source": "USPS Postal Bulletin 22509 (round each measurement to the nearest whole inch, divide by 166 and round up to the next whole pound), https://about.usps.com/postal-bulletin/2018/pb22509/html/updt_002.htm (retrieved 2026-10-05); hand calculation in content.mdx: 1,728 ÷ 166 = 10.41, up to 11 lb, more than 5 lb"
    },
    {
      "given": {
        "sys": "metric",
        "l": 0.36,
        "w": 0.25,
        "h": 0.16,
        "r": "nearest",
        "divm": 5000
      },
      "expect": {
        "dimWeight": 2.88,
        "dimRounded": 3,
        "volume": 14400
      },
      "source": "FedEx UK, \"Understand dimensional weight\" (36 × 25 × 16 cm ÷ 5,000 is a DIM weight of 3 kg), https://www.fedex.com/en-gb/how-to/calculate-costs/dimensional-weight.html (retrieved 2026-10-05); hand calculation in content.mdx: 14,400 ÷ 5,000 = 2.88, up to 3 kg"
    },
    {
      "given": {
        "sys": "us",
        "l": 0.31496,
        "w": 0.26924,
        "h": 0.21589999999999998,
        "r": "up",
        "div": 139,
        "wt": 6.35029318
      },
      "expect": {
        "volume": 1287,
        "dimWeight": 9.258992805755396,
        "dimRounded": 10,
        "billable": 14,
        "result": "14 lb, by weight"
      },
      "source": "FedEx, \"What is dimensional weight?\" (L × W × H in inches, each rounded to the nearest whole inch, ÷ 139), https://www.fedex.com/en-us/shipping/packaging/what-is-dimensional-weight.html (retrieved 2026-10-05); hand calculation in content.mdx: 13 × 11 × 9 = 1,287 ÷ 139 = 9.26, up to 10 lb, less than 14 lb"
    },
    {
      "given": {
        "sys": "us",
        "l": 0.31496,
        "w": 0.26924,
        "h": 0.21589999999999998,
        "r": "nearest",
        "div": 139
      },
      "expect": {
        "volume": 1188,
        "dimRounded": 9
      },
      "source": "USPS Postal Bulletin 22509 (round each measurement to the nearest whole inch, divide by 166 and round up to the next whole pound), https://about.usps.com/postal-bulletin/2018/pb22509/html/updt_002.htm (retrieved 2026-10-05) (nearest whole inch); hand calculation in content.mdx: 12 × 11 × 9 = 1,188 ÷ 139 = 8.55, up to 9 lb"
    }
  ],
  "sources": [
    "FedEx, \"What is dimensional weight?\": L × W × H in inches, each side rounded to the nearest whole inch, ÷ 139. https://www.fedex.com/en-us/shipping/packaging/what-is-dimensional-weight.html (retrieved 2026-10-05)",
    "FedEx UK, \"Understand dimensional weight\": the 5,000 cm³ per kg divisor and the 36 × 25 × 16 cm example (3 kg). https://www.fedex.com/en-gb/how-to/calculate-costs/dimensional-weight.html (retrieved 2026-10-05)",
    "USPS Postal Bulletin 22509: round each side to the nearest whole inch, divide by 166 and round up to the next whole pound, for parcels over 1 cubic foot. https://about.usps.com/postal-bulletin/2018/pb22509/html/updt_002.htm (retrieved 2026-10-05)"
  ],
  "related": [
    "cbm",
    "freight-class",
    "container-pallet"
  ],
  "changelog": []
}