{
  "name": "Puppy growth completion curves by size class",
  "description": "Percentage of adult bodyweight reached at each age, by dog size class. Anchor points are the model; weekly values are linear interpolation between them. The curves are fitted to the Salt et al. 2017 supporting data (9,792,958 usable veterinary weight records of 14,957,947), and sit within a mean absolute error of 1.07 percentage points of the observed medians. The error bands are not a measured prediction error: that needs individual dogs followed to maturity rather than population medians. See https://puppyweightcalculator.co/methodology/ for provenance and limitations.",
  "licence": "CC BY 4.0",
  "attribution": "puppyweightcalculator.co",
  "provenance": {
    "dataset": "Salt et al. 2017 supporting data",
    "doi": "10.17638/datacat.liverpool.ac.uk/377",
    "licence": "CC BY 4.0",
    "records": 14957947,
    "recordsUsed": 9792958,
    "fittedOn": "2026-07-28",
    "meanAbsoluteErrorPoints": 1.07
  },
  "units": {
    "age": "weeks",
    "weight": "pounds",
    "percent": "percent of adult bodyweight"
  },
  "lbPerKg": 2.2046226,
  "sizeClasses": {
    "toy": {
      "adultLb": [
        3,
        12
      ],
      "maturityWeeks": 52
    },
    "small": {
      "adultLb": [
        12,
        25
      ],
      "maturityWeeks": 56
    },
    "medium": {
      "adultLb": [
        25,
        50
      ],
      "maturityWeeks": 60
    },
    "large": {
      "adultLb": [
        50,
        90
      ],
      "maturityWeeks": 78
    },
    "giant": {
      "adultLb": [
        90,
        180
      ],
      "maturityWeeks": 96
    }
  },
  "anchors": {
    "toy": [
      {
        "weeks": 8,
        "pct": 28.1
      },
      {
        "weeks": 12,
        "pct": 40.2
      },
      {
        "weeks": 16,
        "pct": 52.4
      },
      {
        "weeks": 20,
        "pct": 62.6
      },
      {
        "weeks": 26,
        "pct": 73.9
      },
      {
        "weeks": 34,
        "pct": 82.5
      },
      {
        "weeks": 40,
        "pct": 87.3
      },
      {
        "weeks": 52,
        "pct": 100
      }
    ],
    "small": [
      {
        "weeks": 8,
        "pct": 23
      },
      {
        "weeks": 12,
        "pct": 35.6
      },
      {
        "weeks": 16,
        "pct": 48.8
      },
      {
        "weeks": 20,
        "pct": 60
      },
      {
        "weeks": 26,
        "pct": 73.3
      },
      {
        "weeks": 34,
        "pct": 82
      },
      {
        "weeks": 40,
        "pct": 86.8
      },
      {
        "weeks": 52,
        "pct": 92
      },
      {
        "weeks": 56,
        "pct": 100
      }
    ],
    "medium": [
      {
        "weeks": 8,
        "pct": 19.3
      },
      {
        "weeks": 12,
        "pct": 31.4
      },
      {
        "weeks": 16,
        "pct": 44.7
      },
      {
        "weeks": 20,
        "pct": 56.2
      },
      {
        "weeks": 26,
        "pct": 69.7
      },
      {
        "weeks": 34,
        "pct": 80.7
      },
      {
        "weeks": 40,
        "pct": 86.5
      },
      {
        "weeks": 52,
        "pct": 89.9
      },
      {
        "weeks": 60,
        "pct": 100
      }
    ],
    "large": [
      {
        "weeks": 8,
        "pct": 15.3
      },
      {
        "weeks": 12,
        "pct": 27.3
      },
      {
        "weeks": 16,
        "pct": 40.7
      },
      {
        "weeks": 20,
        "pct": 52.6
      },
      {
        "weeks": 26,
        "pct": 67.9
      },
      {
        "weeks": 34,
        "pct": 80.2
      },
      {
        "weeks": 40,
        "pct": 86
      },
      {
        "weeks": 52,
        "pct": 89.4
      },
      {
        "weeks": 65,
        "pct": 96.8
      },
      {
        "weeks": 78,
        "pct": 100
      }
    ],
    "giant": [
      {
        "weeks": 8,
        "pct": 11.9
      },
      {
        "weeks": 12,
        "pct": 22.9
      },
      {
        "weeks": 16,
        "pct": 35.4
      },
      {
        "weeks": 20,
        "pct": 47.3
      },
      {
        "weeks": 26,
        "pct": 62.6
      },
      {
        "weeks": 34,
        "pct": 77.7
      },
      {
        "weeks": 40,
        "pct": 84.8
      },
      {
        "weeks": 52,
        "pct": 88.9
      },
      {
        "weeks": 65,
        "pct": 95.9
      },
      {
        "weeks": 78,
        "pct": 96
      },
      {
        "weeks": 90,
        "pct": 99.4
      },
      {
        "weeks": 96,
        "pct": 100
      }
    ]
  },
  "sources": [
    "Salt C, et al. (2017) PLOS ONE 12(9):e0182064. Underlying dataset: doi:10.17638/datacat.liverpool.ac.uk/377 (CC BY 4.0).",
    "FEDIAF Nutritional Guidelines (2021), Table VII-8a, growth-completion equations by size class.",
    "Hawthorne AJ, et al. (2004) J Nutr 134:2027S. Breed-specific logistic growth parameters."
  ]
}