{
  "size_classes": {
    "toy": {
      "adult_weight_lbs": [0, 12],
      "pct_adult_by_week": {
        "12": 0.50
      },
      "pct_adult_by_week_note": "Only week-12 anchor is verified (see sources). Not a full curve.",
      "source_url": "https://www.calculatorsfordogs.com/age-life-stage-calculators/puppy-weight-predictor"
    },
    "small": {
      "adult_weight_lbs": [12, 22],
      "pct_adult_by_week": {},
      "pct_adult_by_week_note": "No verified data point found for this size class at any age.",
      "source_url": null
    },
    "medium": {
      "adult_weight_lbs": [22, 57],
      "pct_adult_by_week": {},
      "pct_adult_by_week_note": "No verified data point found for this size class at any age.",
      "source_url": null
    },
    "large": {
      "adult_weight_lbs": [57, 99],
      "pct_adult_by_week": {},
      "pct_adult_by_week_note": "No verified data point found for this size class at any age.",
      "source_url": null
    },
    "giant": {
      "adult_weight_lbs": [99, null],
      "pct_adult_by_week": {
        "26": 0.50
      },
      "pct_adult_by_week_note": "Only week-26 anchor is verified (see sources). Qualitative note: giant breeds reach ~99% of adult weight at 11-15 months (~week 48-65) per dog-care-knowledge.com citing Hawthorne et al. 2004 -- not included as a week key because the source gives a month range, not a single week.",
      "source_url": "https://www.calculatorsfordogs.com/age-life-stage-calculators/puppy-weight-predictor"
    },
    "_size_class_band_source": "https://www.omnicalculator.com/biology/dog-size (fetched directly; bands are that site's own stated categories, not an independently verified veterinary standard)",
    "_size_class_band_note": "Bucket boundaries are a CONVENTION used to organize this dataset, not a cited scientific classification.",
    "_veterinary_size_categories_kg": {
      "note": "For reference, the actual veterinary source (Salt et al. 2017, PLOS ONE; WALTHAM growth charts) categorizes dogs by adult weight in kg, not lb bands: Category I <6.5kg, II 6.5-9kg, III 9-15kg, IV 15-30kg, V 30-40kg (charts valid to 40kg/88lb; above that requires an individualized chart per vet).",
      "source_url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC5584974/"
    }
  },
  "breeds": [
    {"name": "French Bulldog", "size_class": "medium", "adult_lbs_male": [null, 28], "adult_lbs_female": [null, 28], "note": "AKC standard/profile give a single max weight (28 lb), no sex split, no minimum published.", "source_url": "https://www.akc.org/dog-breeds/french-bulldog/"},
    {"name": "Labrador Retriever", "size_class": "large", "adult_lbs_male": [65, 80], "adult_lbs_female": [55, 70], "note": "From official AKC breed standard.", "source_url": "https://images.akc.org/pdf/breeds/standards/LabradorRetriever.pdf"},
    {"name": "Golden Retriever", "size_class": "large", "adult_lbs_male": [65, 75], "adult_lbs_female": [55, 65], "note": "From official AKC breed standard.", "source_url": "https://images.akc.org/pdf/breeds/standards/GoldenRetriever.pdf"},
    {"name": "German Shepherd Dog", "size_class": "large", "adult_lbs_male": [65, 90], "adult_lbs_female": [50, 70], "note": "Official written standard specifies height only, not weight; figures are from the AKC breed profile page's quick-facts box.", "source_url": "https://www.akc.org/dog-breeds/german-shepherd-dog/"},
    {"name": "Dachshund (Standard)", "size_class": "medium", "adult_lbs_male": [16, 32], "adult_lbs_female": [16, 32], "note": "AKC profile gives one combined range for Standard variety, no sex split. Miniature variety separately listed as 11 lb and under.", "source_url": "https://www.akc.org/dog-breeds/dachshund/"},
    {"name": "Poodle (Standard)", "size_class": "medium", "adult_lbs_male": [60, 70], "adult_lbs_female": [40, 50], "note": "Official written standard specifies height only; figures from AKC breed profile page.", "source_url": "https://www.akc.org/dog-breeds/poodle-standard/"},
    {"name": "Beagle", "size_class": "medium", "adult_lbs_male": [20, 30], "adult_lbs_female": [20, 30], "note": "Official standard specifies height classes only (13in and under; 13-15in), not weight. AKC profile gives weight by height class: under 20 lb for 13in-and-under variety, 20-30 lb for 13-15in variety; the 20-30 lb class is used here as representative. No sex split published.", "source_url": "https://www.akc.org/dog-breeds/beagle/"},
    {"name": "Rottweiler", "size_class": "giant", "adult_lbs_male": [95, 135], "adult_lbs_female": [80, 100], "note": "Official written standard specifies height only; figures from AKC breed profile page.", "source_url": "https://www.akc.org/dog-breeds/rottweiler/"},
    {"name": "German Shorthaired Pointer", "size_class": "large", "adult_lbs_male": [55, 70], "adult_lbs_female": [45, 60], "note": "From official AKC breed standard.", "source_url": "https://images.akc.org/pdf/breeds/standards/GermanShorthairedPointer.pdf"},
    {"name": "Bulldog", "size_class": "medium", "adult_lbs_male": [50, 50], "adult_lbs_female": [40, 40], "note": "Official standard gives point estimates only (\"about 50 pounds\" dogs, \"about 40 pounds\" bitches), not ranges.", "source_url": "https://images.akc.org/pdf/breeds/standards/Bulldog.pdf"},
    {"name": "Cavalier King Charles Spaniel", "size_class": "small", "adult_lbs_male": [13, 18], "adult_lbs_female": [13, 18], "note": "Official standard gives one combined range, no sex split (\"weight proportionate to height, between 13 and 18 pounds\").", "source_url": "https://images.akc.org/pdf/breeds/standards/CavalierKingCharlesSpaniel.pdf"},
    {"name": "Yorkshire Terrier", "size_class": "toy", "adult_lbs_male": [null, 7], "adult_lbs_female": [null, 7], "note": "Official standard states a maximum only (\"must not exceed seven pounds\"); no minimum published.", "source_url": "https://images.akc.org/pdf/breeds/standards/YorkshireTerrier.pdf"},
    {"name": "Australian Shepherd", "size_class": "medium", "adult_lbs_male": [50, 65], "adult_lbs_female": [40, 55], "note": "Official written standard specifies height only; figures from AKC breed profile page.", "source_url": "https://www.akc.org/dog-breeds/australian-shepherd/"},
    {"name": "Doberman Pinscher", "size_class": "giant", "adult_lbs_male": [75, 100], "adult_lbs_female": [60, 90], "note": "Official written standard specifies height only; figures from AKC breed profile page.", "source_url": "https://www.akc.org/dog-breeds/doberman-pinscher/"},
    {"name": "Pembroke Welsh Corgi", "size_class": "medium", "adult_lbs_male": [27, 30], "adult_lbs_female": [25, 28], "note": "Official standard: max \"not exceeding 30 lb\" (dogs) / \"not exceeding 28 lb\" (bitches); preferred show weight \"approximately 27 lb\" (dogs) / \"approximately 25 lb\" (bitches) used as the low end.", "source_url": "https://images.akc.org/pdf/breeds/standards/PembrokeWelshCorgi.pdf"},
    {"name": "Miniature Schnauzer", "size_class": "small", "adult_lbs_male": [11, 20], "adult_lbs_female": [11, 20], "note": "Official written standard specifies height only; combined range from AKC breed profile page, no sex split.", "source_url": "https://www.akc.org/dog-breeds/miniature-schnauzer/"},
    {"name": "Boxer", "size_class": "large", "adult_lbs_male": [65, 80], "adult_lbs_female": [50, 65], "note": "Official written standard specifies height only. AKC profile gives male range directly; female stated as \"about 15 lb less than male,\" so female range is computed (65-15 to 80-15).", "source_url": "https://www.akc.org/dog-breeds/boxer/"},
    {"name": "Pomeranian", "size_class": "toy", "adult_lbs_male": [3, 7], "adult_lbs_female": [3, 7], "note": "AKC profile combined range, no sex split.", "source_url": "https://www.akc.org/dog-breeds/pomeranian/"},
    {"name": "Bernese Mountain Dog", "size_class": "large", "adult_lbs_male": [80, 115], "adult_lbs_female": [70, 95], "note": "From AKC breed profile page.", "source_url": "https://www.akc.org/dog-breeds/bernese-mountain-dog/"},
    {"name": "Shih Tzu", "size_class": "small", "adult_lbs_male": [9, 16], "adult_lbs_female": [9, 16], "note": "AKC profile combined range, no sex split.", "source_url": "https://www.akc.org/dog-breeds/shih-tzu/"},
    {"name": "Great Dane", "size_class": "giant", "adult_lbs_male": [140, 175], "adult_lbs_female": [110, 140], "note": "From AKC breed profile page.", "source_url": "https://www.akc.org/dog-breeds/great-dane/"},
    {"name": "Boston Terrier", "size_class": "small", "adult_lbs_male": [12, 25], "adult_lbs_female": [12, 25], "note": "AKC profile combined range, no sex split.", "source_url": "https://www.akc.org/dog-breeds/boston-terrier/"},
    {"name": "Chihuahua", "size_class": "toy", "adult_lbs_male": [null, 6], "adult_lbs_female": [null, 6], "note": "AKC profile states a maximum only (\"not exceeding 6 pounds\"); no minimum published.", "source_url": "https://www.akc.org/dog-breeds/chihuahua/"},
    {"name": "Havanese", "size_class": "toy", "adult_lbs_male": [7, 13], "adult_lbs_female": [7, 13], "note": "AKC profile combined range, no sex split.", "source_url": "https://www.akc.org/dog-breeds/havanese/"},
    {"name": "Border Collie", "size_class": "medium", "adult_lbs_male": [30, 55], "adult_lbs_female": [30, 55], "note": "AKC profile combined range, no sex split.", "source_url": "https://www.akc.org/dog-breeds/border-collie/"},
    {"name": "English Springer Spaniel", "size_class": "medium", "adult_lbs_male": [50, 50], "adult_lbs_female": [40, 40], "note": "AKC profile gives point estimates only (50 lb male, 40 lb female), not ranges.", "source_url": "https://www.akc.org/dog-breeds/english-springer-spaniel/"},
    {"name": "Miniature American Shepherd", "size_class": "medium", "adult_lbs_male": [20, 40], "adult_lbs_female": [20, 40], "note": "AKC profile combined range, applies to both sexes.", "source_url": "https://www.akc.org/dog-breeds/miniature-american-shepherd/"},
    {"name": "Shetland Sheepdog", "size_class": "small", "adult_lbs_male": [15, 25], "adult_lbs_female": [15, 25], "note": "AKC profile combined range, no sex split.", "source_url": "https://www.akc.org/dog-breeds/shetland-sheepdog/"},
    {"name": "Siberian Husky", "size_class": "medium", "adult_lbs_male": [45, 60], "adult_lbs_female": [35, 50], "note": "From AKC breed profile page.", "source_url": "https://www.akc.org/dog-breeds/siberian-husky/"},
    {"name": "Brittany", "size_class": "medium", "adult_lbs_male": [30, 40], "adult_lbs_female": [30, 40], "note": "AKC profile combined range, no sex split.", "source_url": "https://www.akc.org/dog-breeds/brittany/"},
    {"name": "Belgian Malinois", "size_class": "large", "adult_lbs_male": [60, 80], "adult_lbs_female": [40, 60], "note": "From AKC breed profile page.", "source_url": "https://www.akc.org/dog-breeds/belgian-malinois/"},
    {"name": "Cocker Spaniel", "size_class": "medium", "adult_lbs_male": [25, 30], "adult_lbs_female": [20, 25], "note": "From AKC breed profile page.", "source_url": "https://www.akc.org/dog-breeds/cocker-spaniel/"},
    {"name": "Basset Hound", "size_class": "medium", "adult_lbs_male": [40, 65], "adult_lbs_female": [40, 65], "note": "AKC profile combined range, no sex split.", "source_url": "https://www.akc.org/dog-breeds/basset-hound/"},
    {"name": "English Cocker Spaniel", "size_class": "medium", "adult_lbs_male": [28, 34], "adult_lbs_female": [26, 32], "note": "From AKC breed profile page.", "source_url": "https://www.akc.org/dog-breeds/english-cocker-spaniel/"},
    {"name": "Maltese", "size_class": "toy", "adult_lbs_male": [null, 7], "adult_lbs_female": [null, 7], "note": "AKC profile states a maximum only (\"under 7 pounds\"); no minimum published.", "source_url": "https://www.akc.org/dog-breeds/maltese/"},
    {"name": "Pug", "size_class": "small", "adult_lbs_male": [14, 18], "adult_lbs_female": [14, 18], "note": "AKC profile combined range, no sex split.", "source_url": "https://www.akc.org/dog-breeds/pug/"},
    {"name": "Collie", "size_class": "large", "adult_lbs_male": [60, 75], "adult_lbs_female": [50, 65], "note": "From AKC breed profile page.", "source_url": "https://www.akc.org/dog-breeds/collie/"},
    {"name": "Mastiff", "size_class": "giant", "adult_lbs_male": [160, 230], "adult_lbs_female": [120, 170], "note": "From AKC breed profile page.", "source_url": "https://www.akc.org/dog-breeds/mastiff/"}
  ],
  "breeds_excluded_no_weight_published": [
    {"name": "Cane Corso", "reason": "Official standard says only \"Weight - Proportionate to height\"; AKC profile page adds descriptive text (\"often weighing more than 100 pounds\") but no defined min/max range.", "source_url": "https://www.akc.org/dog-breeds/cane-corso/"},
    {"name": "Vizsla", "reason": "Neither the official standard nor the AKC profile page states a weight figure; both give height only (male 22-24in, female 21-23in).", "source_url": "https://www.akc.org/dog-breeds/vizsla/"}
  ],
  "formulas": [
    {
      "name": "Weight-at-4-months x2",
      "formula": "adult_weight = weight_at_16_weeks * 2",
      "applicable_weeks": [14, 18],
      "publisher": "Wisdom Panel",
      "quote": "Multiply your pup's weight at four months by two to get an estimate of their adult weight.",
      "caveat": "Source itself flags this as the least accurate of the methods it discusses, because it ignores breed-size differences in growth rate.",
      "source_url": "https://www.wisdompanel.com/en-us/blog/predicting-puppy-size-potential"
    },
    {
      "name": "Linear extrapolation to 52 weeks",
      "formula": "adult_weight = (current_weight_lbs / current_age_weeks) * 52",
      "publisher": "Omni Calculator",
      "quote": "Adult weight = (Puppy weight / Puppy age in weeks) x 52",
      "caveat": "No scientific citation given by the source; growth is not linear, so this is least accurate for large/giant breeds whose growth extends well past 52 weeks.",
      "source_url": "https://www.omnicalculator.com/biology/dog-size"
    },
    {
      "name": "Percentage-of-adult-weight interpolation",
      "formula": "adult_weight = current_weight / pct_adult_at_current_age_for_size_class",
      "publisher": "General veterinary-growth-research method (WALTHAM/Salt et al. 2017 centile tracking is the clinical implementation of this family of method)",
      "quote": null,
      "caveat": "This is the method described as standard by multiple sources, but no source was found that publishes a full, openly accessible percentage table online; WALTHAM's own tool implements it as multi-point centile tracking rather than a single fixed lookup value.",
      "source_url": "https://www.waltham.com/s3media/2020-05/completeguidetowalthampuppygrowthcharts_final.pdf"
    }
  ],
  "sources": [
    {"title": "Growth standard charts for monitoring bodyweight in dogs of different sizes (Salt et al., PLOS ONE, 2017)", "url": "https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0182064", "type": "primary_academic"},
    {"title": "Growth standard charts for monitoring bodyweight in dogs of different sizes (PMC full text)", "url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC5584974/", "type": "primary_academic"},
    {"title": "Correction notice re: data availability (2024)", "url": "https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0314711", "type": "primary_academic"},
    {"title": "Complete Guide to WALTHAM Puppy Growth Charts (PDF)", "url": "https://www.waltham.com/s3media/2020-05/completeguidetowalthampuppygrowthcharts_final.pdf", "type": "veterinary_industry"},
    {"title": "WALTHAM Puppy Growth Charts resource page", "url": "https://www.waltham.com/resources/puppy-growth-charts", "type": "veterinary_industry", "note": "403 on direct fetch; referenced via the PDF above and secondary summaries"},
    {"title": "Body-weight changes during growth in puppies of different breeds (Hawthorne et al., J Nutr, 2004)", "url": "https://pubmed.ncbi.nlm.nih.gov/15284394/", "type": "primary_academic", "note": "Abstract/full text not accessible with available tools; no numeric data from this paper is used in this dataset"},
    {"title": "Puppy Weight Chart (cites Hawthorne 2004 for the 9-10mo / 11-15mo milestones)", "url": "https://www.dog-care-knowledge.com/puppy-weight-chart.html", "type": "secondary"},
    {"title": "Puppy Weight Predictor (source of the two verified pct_adult_by_week anchors)", "url": "https://www.calculatorsfordogs.com/age-life-stage-calculators/puppy-weight-predictor", "type": "secondary_calculator"},
    {"title": "Dog Size Calculator (source of the size-class lb bands and the linear-extrapolation formula)", "url": "https://www.omnicalculator.com/biology/dog-size", "type": "secondary_calculator"},
    {"title": "3 ways to predict how big your puppy will get (source of the 4-month x2 formula)", "url": "https://www.wisdompanel.com/en-us/blog/predicting-puppy-size-potential", "type": "secondary_commercial"},
    {"title": "MSD Veterinary Manual - Nutritional Requirements of Small Animals", "url": "https://www.msdvetmanual.com/management-and-nutrition/nutrition-small-animals/nutritional-requirements-of-small-animals", "type": "veterinary_reference"},
    {"title": "Most Popular Dog Breeds of 2025 (AKC ranking used for the breed list)", "url": "https://www.akc.org/expert-advice/dog-breeds/most-popular-dog-breeds-2025/", "type": "primary_akc"}
  ]
}