{
    "name": "Ideal Weight Calculator",
    "url": "https://calculators.geekmidst.com/calculators/ideal-weight-calculator",
    "markdown": "https://calculators.geekmidst.com/calculators/ideal-weight-calculator.md",
    "category": "Health & fitness",
    "description": "Calculate ideal body weight for your height and sex with the Devine, Robinson and Miller formulas, alongside the BMI 18.5–24.9 weight range.",
    "summary": "“Ideal” body weight formulas add a fixed amount for every inch over 5 feet. The Devine formula, published in 1974 for drug dosing, is still the one most used in clinical practice.",
    "also_called": [
        "Ideal body weight calculator",
        "IBW 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": "sex",
            "label": "Sex",
            "type": "segmented",
            "default": "female",
            "options": {
                "female": "Female",
                "male": "Male"
            }
        },
        {
            "name": "units",
            "label": "Units",
            "type": "segmented",
            "default": "metric",
            "options": {
                "metric": "Metric (cm, kg)",
                "us": "US (ft, in, lb)"
            }
        },
        {
            "name": "height_cm",
            "label": "Height",
            "type": "number",
            "default": "170",
            "unit": "cm",
            "shown_when": {
                "units": "metric"
            }
        },
        {
            "name": "height_ft",
            "label": "Height (feet)",
            "type": "number",
            "default": "5",
            "unit": "ft",
            "shown_when": {
                "units": "us"
            }
        },
        {
            "name": "height_in",
            "label": "Height (inches)",
            "type": "number",
            "default": "7",
            "unit": "in",
            "optional": true,
            "shown_when": {
                "units": "us"
            }
        }
    ],
    "outputs": [
        {
            "key": "devine",
            "label": "Devine (1974)",
            "format": "number"
        },
        {
            "key": "robinson",
            "label": "Robinson (1983)",
            "format": "number"
        },
        {
            "key": "miller",
            "label": "Miller (1983)",
            "format": "number"
        },
        {
            "key": "bmi_range",
            "label": "BMI 18.5–24.9 range",
            "format": "text"
        }
    ],
    "formula": {
        "text": "Devine: men 50 kg + 2.3 kg per inch over 5 ft, women 45.5 kg + 2.3 kg;  Robinson: men 52 + 1.9, women 49 + 1.7;  Miller: men 56.2 + 1.41, women 53.1 + 1.36",
        "variables": {
            "inches over 5 ft": "height in inches (cm ÷ 2.54) minus 60",
            "results": "shown in kg (metric) or lb (US)"
        }
    },
    "worked_example": {
        "inputs": {
            "sex": "female",
            "units": "metric",
            "height_cm": "170",
            "height_ft": "5",
            "height_in": "7"
        },
        "steps": [
            "170 cm ÷ 2.54 = 66.93 in, which is 6.93 in over 5 ft.",
            "Devine: 45.5 + 2.3 × 6.93 = 61.4 kg.",
            "Robinson: 49 + 1.7 × 6.93 = 60.8 kg; Miller: 53.1 + 1.36 × 6.93 = 62.5 kg.",
            "BMI range: 18.5 × 1.70² = 53.5 kg to 24.9 × 1.70² = 72.0 kg."
        ],
        "result": "For a woman 170 cm tall the formulas give 60.8–62.5 kg (Devine 61.4 kg), well inside the BMI-based healthy range of 53.5–72.0 kg."
    },
    "interpretation": "These are single reference weights, not targets. The BMI range shows how wide a healthy weight can be at the same height; frame size, muscle and age all shift where you sit within it. Clinicians mainly use the Devine value to dose certain medicines and set ventilator volumes.",
    "assumptions": [
        "Adults 5 ft (152.4 cm) or taller; the formulas are not defined below that height.",
        "Formulas as compiled by Pai and Paloucek (2000)."
    ],
    "limitations": [
        "The formulas were not derived from health outcomes; Devine’s was an estimate for drug dosing.",
        "They take no account of body composition, frame size, age or ethnicity."
    ],
    "rules": null,
    "faqs": [
        {
            "question": "Which formula is most accurate?",
            "answer": "None is “accurate” in a health sense. They give similar results near average heights and diverge for very short or very tall people; the BMI range is a broader guide."
        },
        {
            "question": "Why is there no result under 5 feet?",
            "answer": "All three formulas start at 5 feet. Some clinicians subtract per inch below that, but that is an extrapolation the original authors did not publish."
        }
    ],
    "sources": [
        {
            "title": "Pai MP, Paloucek FP. The origin of the “ideal” body weight equations. Ann Pharmacother, 2000",
            "url": "https://www.researchgate.net/profile/Manjunath-Pai/publication/258125580_The_Origin_of_the_Ideal_Body_Weight_Equations/links/0a85e53bfe73e41443000000/The-Origin-of-the-Ideal-Body-Weight-Equations.pdf"
        }
    ],
    "related": [
        {
            "name": "Healthy Weight Calculator",
            "url": "https://calculators.geekmidst.com/calculators/healthy-weight-calculator"
        },
        {
            "name": "BMI Calculator",
            "url": "https://calculators.geekmidst.com/calculators/bmi-calculator"
        },
        {
            "name": "Lean Body Mass Calculator",
            "url": "https://calculators.geekmidst.com/calculators/lean-body-mass-calculator"
        },
        {
            "name": "Body Fat Calculator",
            "url": "https://calculators.geekmidst.com/calculators/body-fat-calculator"
        }
    ],
    "disclaimer": "This is a general screening estimate for adults, not medical advice or a diagnosis. Talk to a qualified health professional about your health.",
    "publisher": "GM¹X CalcVerse"
}