{"success":true,"version":"v1","request":{"tool":"get_calculator_schema","calculator_id":"adjusted-body-weight"},"result":{"entity_type":"calculator","id":"adjusted-body-weight","calculator_id":"adjusted-body-weight","canonical_url":"https://tttkmbb.com/medical/adjusted-body-weight","name":"Adjusted Body Weight Calculator","title":"Adjusted Body Weight Calculator – Devine Ideal Weight plus 40% of Excess Weight for Dosing","category":"medical","category_name":"Medical & Clinical","tool_name":"calculate_adjusted_body_weight","featured_mcp_tool":false,"description":"Computes ideal body weight (Devine) and adjusted body weight (IBW + 0.4 × (actual − IBW)) used for drug dosing and creatinine clearance in people whose weight exceeds 120% of ideal.","use_when":"You need the dosing weight for hydrophilic drugs (e.g. aminoglycosides) or the Cockcroft-Gault weight in an overweight adult.","do_not_use_when":"The drug is dosed on actual weight (many lipophilic drugs), the person is under 18 or shorter than 152 cm, where Devine's formula is not validated.","inputs":[{"name":"sex","label":"Sex","type":"enum","required":true,"values":[{"value":"male","label":"Male","aliases":["m","man"]},{"value":"female","label":"Female","aliases":["f","woman"]}],"description":"Sex used to select the formula coefficients or thresholds.","example":"male"},{"name":"height_cm","label":"Height","type":"number","unit":"cm","required":true,"min":120,"max":260,"description":"Height in centimetres.","example":175},{"name":"weight_kg","label":"Actual weight","type":"number","unit":"kg","required":true,"max":700,"exclusive_min":0,"description":"Actual body weight in kilograms.","example":100},{"name":"correction_factor","label":"Correction factor","type":"number","required":false,"default":0.4,"min":0.2,"max":0.5,"description":"Fraction of the excess weight added to IBW; 0.4 is standard, some protocols use 0.3.","example":0.4}],"outputs":[{"name":"ideal_body_weight_kg","label":"Ideal body weight (Devine)","type":"number","unit":"kg","decimals":1,"description":"50 kg (male) or 45.5 kg (female) + 2.3 kg per inch over 5 ft."},{"name":"percent_of_ideal","label":"Actual as % of ideal","type":"number","unit":"%","decimals":1,"description":"weight_kg / IBW × 100."},{"name":"adjusted_body_weight_kg","label":"Adjusted body weight","type":"number","unit":"kg","decimals":1,"description":"IBW + factor × (actual − IBW)."},{"name":"adjusted_weight_applies","label":"Adjusted weight applies","type":"boolean","decimals":4,"description":"True when actual weight exceeds 120% of ideal."},{"name":"dosing_weight_kg","label":"Suggested dosing weight","type":"number","unit":"kg","decimals":1,"description":"Adjusted weight when it applies, otherwise actual weight."},{"name":"weight_basis","label":"Basis","type":"string","decimals":4,"description":"Which weight the suggestion uses and why."}],"input_schema":{"type":"object","properties":{"sex":{"description":"Sex used to select the formula coefficients or thresholds.","type":"string","enum":["male","female"],"examples":["male"]},"height_cm":{"description":"Height in centimetres. Unit: cm.","type":"number","minimum":120,"maximum":260,"examples":[175],"x-unit":"cm"},"weight_kg":{"description":"Actual body weight in kilograms. Unit: kg.","type":"number","maximum":700,"exclusiveMinimum":0,"examples":[100],"x-unit":"kg"},"correction_factor":{"description":"Fraction of the excess weight added to IBW; 0.4 is standard, some protocols use 0.3.","type":"number","minimum":0.2,"maximum":0.5,"default":0.4,"examples":[0.4]}},"additionalProperties":false,"required":["sex","height_cm","weight_kg"]},"output_schema":{"type":"object","properties":{"ideal_body_weight_kg":{"description":"50 kg (male) or 45.5 kg (female) + 2.3 kg per inch over 5 ft. Unit: kg.","type":"number","x-unit":"kg"},"percent_of_ideal":{"description":"weight_kg / IBW × 100. Unit: %.","type":"number","x-unit":"%"},"adjusted_body_weight_kg":{"description":"IBW + factor × (actual − IBW). Unit: kg.","type":"number","x-unit":"kg"},"adjusted_weight_applies":{"description":"True when actual weight exceeds 120% of ideal.","type":"boolean"},"dosing_weight_kg":{"description":"Adjusted weight when it applies, otherwise actual weight. Unit: kg.","type":"number","x-unit":"kg"},"weight_basis":{"description":"Which weight the suggestion uses and why.","type":"string"}}},"formula":"IBW = 50 (male) or 45.5 (female) + 2.3 × (height_cm / 2.54 − 60); adjusted_BW = IBW + correction_factor × (weight_kg − IBW), applied when weight_kg > 1.2 × IBW","method":"The 0.4 factor assumes about 40% of excess adipose tissue is water and drug-distributing; it is a convention from aminoglycoside pharmacokinetics rather than a universal rule, and drug-specific labelling takes precedence. Results are informational only and not a substitute for clinical judgement or medical advice.","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":"2026-09-24"},{"name":"Winter MA et al. (2012) Impact of various body weights and serum creatinine concentrations on the bias and accuracy of the Cockcroft-Gault equation, Pharmacotherapy 32:604-612","url":"https://pubmed.ncbi.nlm.nih.gov/22576791/","type":"peer_reviewed","retrieved_at":"2026-09-24"}],"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, 100 kg","inputs":{"sex":"male","height_cm":175,"weight_kg":100},"expected":{"ideal_body_weight_kg":70.5,"percent_of_ideal":141.9,"adjusted_body_weight_kg":82.3,"adjusted_weight_applies":true,"dosing_weight_kg":82.3},"url":"https://tttkmbb.com/api/v1/calculate/adjusted-body-weight?sex=male&height_cm=175&weight_kg=100"},{"name":"Female, 160 cm, 60 kg","inputs":{"sex":"female","height_cm":160,"weight_kg":60},"expected":{"ideal_body_weight_kg":52.4,"percent_of_ideal":114.5,"adjusted_weight_applies":false,"dosing_weight_kg":60},"url":"https://tttkmbb.com/api/v1/calculate/adjusted-body-weight?sex=female&height_cm=160&weight_kg=60"}],"faq":[{"q":"Why 120% of ideal?","a":"Below that, the difference between actual and adjusted weight is small; most references (and the Winter 2012 analysis) start using adjusted weight around 120–130% of IBW."},{"q":"What if actual weight is below ideal?","a":"Actual weight is used for dosing; the adjusted-weight formula is not meant for underweight patients."}],"tags":["adjusted body weight","ideal body weight","devine","dosing weight","obesity dosing"],"related":[{"calculator_id":"ideal-weight","reason":"Ideal weight by Devine, Robinson, Miller and Hamwi."},{"calculator_id":"creatinine-clearance","reason":"Cockcroft-Gault with adjusted weight."},{"calculator_id":"bmi","reason":"Weight classification for the same height and weight."}],"links":{"html":"https://tttkmbb.com/medical/adjusted-body-weight","markdown":"https://tttkmbb.com/medical/adjusted-body-weight.md","json":"https://tttkmbb.com/medical/adjusted-body-weight.json","api":"https://tttkmbb.com/api/v1/calculate/adjusted-body-weight","schema":"https://tttkmbb.com/api/v1/calculators/adjusted-body-weight","openapi":"https://tttkmbb.com/openapi.json","mcp":"https://tttkmbb.com/mcp"},"version":"v1","updated_at":"2026-09-24"},"timestamp":"2026-09-24T01:50:25Z","next_actions":[{"tool":"run_calculator","calculator_id":"adjusted-body-weight","reason":"Run Adjusted Body Weight Calculator with the inputs above."}],"links":{"markdown":"https://tttkmbb.com/medical/adjusted-body-weight.md"}}