{"success":true,"version":"v1","request":{"tool":"get_calculator_schema","calculator_id":"ideal-weight"},"result":{"entity_type":"calculator","id":"ideal-weight","calculator_id":"ideal-weight","canonical_url":"https://tttkmbb.com/health/ideal-weight","name":"Ideal Weight Calculator","title":"Ideal Body Weight Calculator – Devine, Robinson, Miller and Hamwi Formulas","category":"health","category_name":"Health","tool_name":"calculate_ideal_weight","featured_mcp_tool":false,"description":"Computes ideal body weight from height and sex with the four common clinical formulas (Devine, Robinson, Miller, Hamwi) and the BMI 18.5–24.9 healthy range.","use_when":"You need a reference 'ideal' weight for an adult, e.g. for drug dosing (Devine) or general guidance, or the healthy weight range for a height.","do_not_use_when":"The person is under 18 or you need body-composition targets; the formulas are population averages, not individual prescriptions.","inputs":[{"name":"sex","label":"Biological sex","type":"enum","required":true,"values":[{"value":"male","label":"Male","aliases":["m","man"]},{"value":"female","label":"Female","aliases":["f","woman"]}],"description":"Biological sex used to select the formula coefficients.","example":"male"},{"name":"height_cm","label":"Height","type":"number","unit":"cm","required":true,"min":120,"max":260,"description":"Height in centimetres. Formulas are defined for heights above 152.4 cm (5 ft).","example":175}],"outputs":[{"name":"devine_kg","label":"Devine (1974)","type":"number","unit":"kg","decimals":1,"description":"Most widely used in pharmacology."},{"name":"robinson_kg","label":"Robinson (1983)","type":"number","unit":"kg","decimals":1,"description":"Robinson et al. modification."},{"name":"miller_kg","label":"Miller (1983)","type":"number","unit":"kg","decimals":1,"description":"Miller et al. modification."},{"name":"hamwi_kg","label":"Hamwi (1964)","type":"number","unit":"kg","decimals":1,"description":"Hamwi method."},{"name":"healthy_bmi_range_min_kg","label":"Healthy BMI range (min)","type":"number","unit":"kg","decimals":1,"description":"Weight at BMI 18.5."},{"name":"healthy_bmi_range_max_kg","label":"Healthy BMI range (max)","type":"number","unit":"kg","decimals":1,"description":"Weight at BMI 24.9."}],"input_schema":{"type":"object","properties":{"sex":{"description":"Biological sex used to select the formula coefficients.","type":"string","enum":["male","female"],"examples":["male"]},"height_cm":{"description":"Height in centimetres. Formulas are defined for heights above 152.4 cm (5 ft). Unit: cm.","type":"number","minimum":120,"maximum":260,"examples":[175],"x-unit":"cm"}},"additionalProperties":false,"required":["sex","height_cm"]},"output_schema":{"type":"object","properties":{"devine_kg":{"description":"Most widely used in pharmacology. Unit: kg.","type":"number","x-unit":"kg"},"robinson_kg":{"description":"Robinson et al. modification. Unit: kg.","type":"number","x-unit":"kg"},"miller_kg":{"description":"Miller et al. modification. Unit: kg.","type":"number","x-unit":"kg"},"hamwi_kg":{"description":"Hamwi method. Unit: kg.","type":"number","x-unit":"kg"},"healthy_bmi_range_min_kg":{"description":"Weight at BMI 18.5. Unit: kg.","type":"number","x-unit":"kg"},"healthy_bmi_range_max_kg":{"description":"Weight at BMI 24.9. Unit: kg.","type":"number","x-unit":"kg"}}},"formula":"With h = inches over 5 ft (60 in): Devine male 50 + 2.3h, female 45.5 + 2.3h; Robinson male 52 + 1.9h, female 49 + 1.7h; Miller male 56.2 + 1.41h, female 53.1 + 1.36h; Hamwi male 48 + 2.7h, female 45.5 + 2.2h. For heights under 5 ft the same slope is applied downward.","sources":[{"name":"Pai MP, Paloucek FP (2000) The origin of the 'ideal' body weight equations, Ann Pharmacother 34:1066-1069","url":"https://pubmed.ncbi.nlm.nih.gov/10981254/","type":"peer_reviewed","retrieved_at":"2026-09-23"},{"name":"WHO – A healthy lifestyle: body mass index","url":"https://www.who.int/europe/news-room/fact-sheets/item/a-healthy-lifestyle---who-recommendations","type":"standard","retrieved_at":"2026-09-23"}],"freshness":{"type":"static","max_age_seconds":null,"note":"Deterministic formula with fixed constants; results never go stale. Inputs supplied by the caller determine the output."},"examples":[{"name":"Male, 175 cm","inputs":{"sex":"male","height_cm":175},"expected":{"devine_kg":70.5,"robinson_kg":68.9,"miller_kg":68.7,"hamwi_kg":72,"healthy_bmi_range_min_kg":56.7,"healthy_bmi_range_max_kg":76.3},"url":"https://tttkmbb.com/api/v1/calculate/ideal-weight?sex=male&height_cm=175"},{"name":"Female, 160 cm","inputs":{"sex":"female","height_cm":160},"expected":{"devine_kg":52.4,"robinson_kg":54.1},"url":"https://tttkmbb.com/api/v1/calculate/ideal-weight?sex=female&height_cm=160"}],"faq":[{"q":"Why do the formulas disagree?","a":"Each was fitted to a different reference population and purpose (Devine for drug dosing, Hamwi for dietetics). Differences of 2–4 kg are normal; the BMI range is a broader, evidence-based guide."},{"q":"Is ideal weight the same as healthy weight?","a":"No. 'Ideal' formulas give a single point estimate; a healthy weight is any weight in the BMI 18.5–24.9 range for adults, with body composition taken into account."}],"tags":["ideal weight","ideal body weight","devine","robinson","miller","hamwi","ibw"],"related":[{"calculator_id":"bmi","reason":"Check where a current weight falls in the BMI categories."}],"links":{"html":"https://tttkmbb.com/health/ideal-weight","markdown":"https://tttkmbb.com/health/ideal-weight.md","json":"https://tttkmbb.com/health/ideal-weight.json","api":"https://tttkmbb.com/api/v1/calculate/ideal-weight","schema":"https://tttkmbb.com/api/v1/calculators/ideal-weight","openapi":"https://tttkmbb.com/openapi.json","mcp":"https://tttkmbb.com/mcp"},"version":"v1","updated_at":"2026-09-23"},"timestamp":"2026-09-23T23:31:58Z"}