{
    "name": "Dog Age Calculator",
    "url": "https://calculators.geekmidst.com/calculators/dog-age-calculator",
    "markdown": "https://calculators.geekmidst.com/calculators/dog-age-calculator.md",
    "category": "Everyday tools",
    "description": "Convert your dog’s age to human-equivalent years using the AVMA chart for small or medium dogs or the 2020 epigenetic formula 16 ln(age) + 31.",
    "summary": "There is no single exact conversion. This calculator shows two published methods: the American Veterinary Medical Association chart, and the DNA-methylation formula of Wang et al. (2020).",
    "also_called": [
        "Dog years calculator",
        "Pet age equivalent calculator"
    ],
    "applies_to": "Worldwide",
    "last_updated": "2026-10-29",
    "computation": "Results are computed in the visitor’s browser on the HTML page. This API describes the calculator; it does not compute results.",
    "inputs": [
        {
            "name": "years",
            "label": "Dog’s age: years",
            "type": "number",
            "default": "4",
            "unit": "years"
        },
        {
            "name": "months",
            "label": "Months",
            "type": "number",
            "default": "0",
            "unit": "months",
            "optional": true
        },
        {
            "name": "method",
            "label": "Method",
            "type": "select",
            "default": "avma_medium",
            "options": {
                "avma_small": "AVMA chart: small dog (up to 20 lb / 9 kg)",
                "avma_medium": "AVMA chart: medium dog (21–50 lb / 9.5–23 kg)",
                "epigenetic": "Epigenetic clock: 16 × ln(age) + 31 (Wang et al. 2020)"
            }
        }
    ],
    "outputs": [
        {
            "key": "human_age",
            "label": "Human-equivalent age",
            "format": "number"
        },
        {
            "key": "age_years",
            "label": "Dog’s age in years",
            "format": "number"
        },
        {
            "key": "method_used",
            "label": "Method",
            "format": "text"
        }
    ],
    "formula": {
        "text": "AVMA chart (medium dog): 15, 24, 28, 32, 36, 42, 47, 51, 56, 60, 65, 69, 74, 78, 83, 87 at ages 1–16, interpolated between whole years;  Epigenetic: Human age = 16 × ln(Dog age) + 31",
        "variables": {
            "ln": "natural logarithm",
            "Dog age": "in years"
        }
    },
    "worked_example": {
        "inputs": {
            "years": "4",
            "months": "0",
            "method": "avma_medium"
        },
        "steps": [
            "The AVMA chart gives 15 human years for year one, 24 by year two, then 28, and 32 at age 4.",
            "For comparison, the epigenetic formula gives 16 × ln 4 + 31 = 16 × 1.386 + 31 = 53.2."
        ],
        "result": "A 4-year-old medium-sized dog is about 32 in human years on the AVMA chart, or about 53 by the epigenetic formula."
    },
    "interpretation": "The methods disagree because they measure different things: the AVMA chart reflects typical life stage and lifespan, while the epigenetic clock compares DNA-methylation changes and suggests dogs age very fast when young. Neither is exact for an individual dog.",
    "assumptions": [
        "The AVMA chart is used from 1 to 16 years, with straight-line interpolation between whole years.",
        "The epigenetic formula was derived from 104 Labrador retrievers."
    ],
    "limitations": [
        "Large and giant breeds age faster than the charted sizes and are not covered by the AVMA chart here.",
        "Cats are not included because a full verified chart was not available."
    ],
    "rules": null,
    "faqs": [
        {
            "question": "Is one dog year equal to seven human years?",
            "answer": "No. Both methods show dogs age much faster in their first two years and more slowly afterwards; the 7× rule is a myth."
        },
        {
            "question": "Which method should I use?",
            "answer": "For life-stage care, the AVMA chart and your vet’s advice are the practical choice. The epigenetic formula is a research finding based on one breed."
        }
    ],
    "sources": [
        {
            "title": "AVMA: Pets Age Faster (age chart)",
            "url": "https://ebusiness.avma.org/files/productdownloads/PetsAgeFasterPoster.pdf"
        },
        {
            "title": "AVMA: Senior Pets (human equivalents by dog size)",
            "url": "https://ebusiness.avma.org/files/productdownloads/SeniorPets_En.pdf"
        },
        {
            "title": "AKC: How to Calculate Dog Years to Human Years",
            "url": "https://www.akc.org/expert-advice/health/how-to-calculate-dog-years-to-human-years/"
        },
        {
            "title": "Sci.News: report on Wang et al., Cell Systems 2020 (doi:10.1016/j.cels.2020.06.006)",
            "url": "https://www.sci.news/biology/dog-aging-08614.html"
        }
    ],
    "related": [
        {
            "name": "Age Calculator",
            "url": "https://calculators.geekmidst.com/calculators/age-calculator"
        },
        {
            "name": "Pet Food Portion Calculator",
            "url": "https://calculators.geekmidst.com/calculators/pet-food-portion-calculator"
        },
        {
            "name": "Pet Daily Water Need Calculator",
            "url": "https://calculators.geekmidst.com/calculators/pet-daily-water-need-calculator"
        }
    ],
    "disclaimer": null,
    "publisher": "GM¹X CalcVerse"
}