{"success":true,"version":"v1","request":{"tool":"get_calculator_schema","calculator_id":"creatinine-clearance"},"result":{"entity_type":"calculator","id":"creatinine-clearance","calculator_id":"creatinine-clearance","canonical_url":"https://tttkmbb.com/medical/creatinine-clearance","name":"Creatinine Clearance Calculator","title":"Creatinine Clearance Calculator – Cockcroft-Gault Equation (Actual, Ideal and Adjusted Weight)","category":"medical","category_name":"Medical & Clinical","tool_name":"calculate_creatinine_clearance","featured_mcp_tool":false,"description":"Estimates creatinine clearance in mL/min with the Cockcroft-Gault equation from age, weight, sex and serum creatinine, and, when height is given, also reports the values using ideal (Devine) and adjusted body weight.","use_when":"You need the creatinine clearance used by drug-dosing references (renal dose adjustment) for an adult.","do_not_use_when":"You need a BSA-indexed CKD stage (use egfr), the person is under 18, or creatinine is changing rapidly (acute kidney injury).","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":"age_years","label":"Age","type":"number","unit":"years","required":true,"min":18,"max":120,"description":"Age in years.","example":40},{"name":"weight_kg","label":"Weight","type":"number","unit":"kg","required":true,"max":700,"exclusive_min":0,"description":"Actual body weight in kilograms.","example":70},{"name":"creatinine","label":"Serum creatinine","type":"number","required":true,"max":4000,"exclusive_min":0,"description":"Serum creatinine in the unit given by creatinine_unit.","example":1},{"name":"creatinine_unit","label":"Creatinine unit","type":"enum","required":false,"default":"mg_dl","values":[{"value":"mg_dl","label":"mg/dL","aliases":["mg/dl","mgdl"]},{"value":"umol_l","label":"µmol/L","aliases":["umol/l","µmol/l","micromol/l","umol","mcmol/l"]}],"description":"Unit of the serum creatinine value (1 mg/dL = 88.4 µmol/L).","example":"mg_dl"},{"name":"height_cm","label":"Height","type":"number","unit":"cm","required":false,"min":120,"max":260,"description":"Optional height; enables ideal-body-weight and adjusted-body-weight variants.","example":175}],"outputs":[{"name":"creatinine_clearance_ml_min","label":"Creatinine clearance (actual weight)","type":"number","unit":"mL/min","decimals":1,"description":"Cockcroft-Gault clearance using actual body weight."},{"name":"ideal_body_weight_kg","label":"Ideal body weight (Devine)","type":"number","unit":"kg","decimals":1,"description":"Only when height_cm is given."},{"name":"adjusted_body_weight_kg","label":"Adjusted body weight","type":"number","unit":"kg","decimals":1,"description":"IBW + 0.4 × (actual − IBW); only when height_cm is given."},{"name":"creatinine_clearance_ibw_ml_min","label":"Clearance (ideal weight)","type":"number","unit":"mL/min","decimals":1,"description":"Cockcroft-Gault using ideal body weight; only when height_cm is given."},{"name":"creatinine_clearance_adjusted_ml_min","label":"Clearance (adjusted weight)","type":"number","unit":"mL/min","decimals":1,"description":"Cockcroft-Gault using adjusted body weight; only when height_cm is given."},{"name":"weight_note","label":"Weight guidance","type":"string","decimals":4,"description":"Which weight is commonly used for this body size."}],"input_schema":{"type":"object","properties":{"sex":{"description":"Sex used to select the formula coefficients or thresholds.","type":"string","enum":["male","female"],"examples":["male"]},"age_years":{"description":"Age in years. Unit: years.","type":"number","minimum":18,"maximum":120,"examples":[40],"x-unit":"years"},"weight_kg":{"description":"Actual body weight in kilograms. Unit: kg.","type":"number","maximum":700,"exclusiveMinimum":0,"examples":[70],"x-unit":"kg"},"creatinine":{"description":"Serum creatinine in the unit given by creatinine_unit.","type":"number","maximum":4000,"exclusiveMinimum":0,"examples":[1]},"creatinine_unit":{"description":"Unit of the serum creatinine value (1 mg/dL = 88.4 µmol/L).","type":"string","enum":["mg_dl","umol_l"],"default":"mg_dl","examples":["mg_dl"]},"height_cm":{"description":"Optional height; enables ideal-body-weight and adjusted-body-weight variants. Unit: cm.","type":"number","minimum":120,"maximum":260,"examples":[175],"x-unit":"cm"}},"additionalProperties":false,"required":["sex","age_years","weight_kg","creatinine"]},"output_schema":{"type":"object","properties":{"creatinine_clearance_ml_min":{"description":"Cockcroft-Gault clearance using actual body weight. Unit: mL/min.","type":"number","x-unit":"mL/min"},"ideal_body_weight_kg":{"description":"Only when height_cm is given. Unit: kg.","type":"number","x-unit":"kg"},"adjusted_body_weight_kg":{"description":"IBW + 0.4 × (actual − IBW); only when height_cm is given. Unit: kg.","type":"number","x-unit":"kg"},"creatinine_clearance_ibw_ml_min":{"description":"Cockcroft-Gault using ideal body weight; only when height_cm is given. Unit: mL/min.","type":"number","x-unit":"mL/min"},"creatinine_clearance_adjusted_ml_min":{"description":"Cockcroft-Gault using adjusted body weight; only when height_cm is given. Unit: mL/min.","type":"number","x-unit":"mL/min"},"weight_note":{"description":"Which weight is commonly used for this body size.","type":"string"}}},"formula":"CrCl = (140 − age_years) × weight_kg / (72 × Scr_mg_dl) × 0.85 (if female); IBW (Devine) = 50 (male) or 45.5 (female) + 2.3 × (height_in − 60); adjusted BW = IBW + 0.4 × (weight − IBW)","method":"Cockcroft-Gault (1976) overestimates clearance in obesity when actual weight is used and in low muscle mass; many references use ideal weight when actual is below it and adjusted weight above 120–130% of ideal. Results are informational only and not a substitute for clinical judgement or medical advice.","sources":[{"name":"Cockcroft DW, Gault MH (1976) Prediction of creatinine clearance from serum creatinine, Nephron 16:31-41","url":"https://pubmed.ncbi.nlm.nih.gov/1244564/","type":"peer_reviewed","retrieved_at":"2026-09-24"},{"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, 40 y, 70 kg, creatinine 1.0 mg/dL","inputs":{"sex":"male","age_years":40,"weight_kg":70,"creatinine":1},"expected":{"creatinine_clearance_ml_min":97.2},"url":"https://tttkmbb.com/api/v1/calculate/creatinine-clearance?sex=male&age_years=40&weight_kg=70&creatinine=1"},{"name":"Female, 65 y, 60 kg, 160 cm, creatinine 0.8 mg/dL","inputs":{"sex":"female","age_years":65,"weight_kg":60,"creatinine":0.8,"height_cm":160},"expected":{"creatinine_clearance_ml_min":66.4,"ideal_body_weight_kg":52.4,"creatinine_clearance_ibw_ml_min":58},"url":"https://tttkmbb.com/api/v1/calculate/creatinine-clearance?sex=female&age_years=65&weight_kg=60&creatinine=0.8&height_cm=160"}],"faq":[{"q":"Which weight should I use?","a":"Common practice: actual weight when it is below ideal weight, ideal weight for normal-weight adults, and adjusted weight when actual weight exceeds about 120% of ideal; follow the specific drug's labelling."},{"q":"Why is creatinine clearance different from eGFR?","a":"Cockcroft-Gault is an unindexed estimate in mL/min derived in 1976 for a small male cohort; eGFR (CKD-EPI) is indexed to 1.73 m² and validated for staging CKD, not dosing."}],"tags":["creatinine clearance","cockcroft gault","crcl","renal dosing","kidney function"],"related":[{"calculator_id":"egfr","reason":"CKD-EPI 2021 eGFR for staging kidney disease."},{"calculator_id":"adjusted-body-weight","reason":"Adjusted body weight for dosing in obesity."},{"calculator_id":"ideal-weight","reason":"Ideal body weight formulas."}],"links":{"html":"https://tttkmbb.com/medical/creatinine-clearance","markdown":"https://tttkmbb.com/medical/creatinine-clearance.md","json":"https://tttkmbb.com/medical/creatinine-clearance.json","api":"https://tttkmbb.com/api/v1/calculate/creatinine-clearance","schema":"https://tttkmbb.com/api/v1/calculators/creatinine-clearance","openapi":"https://tttkmbb.com/openapi.json","mcp":"https://tttkmbb.com/mcp"},"version":"v1","updated_at":"2026-09-24"},"timestamp":"2026-09-24T02:01:52Z","next_actions":[{"tool":"run_calculator","calculator_id":"creatinine-clearance","reason":"Run Creatinine Clearance Calculator with the inputs above."}],"links":{"markdown":"https://tttkmbb.com/medical/creatinine-clearance.md"}}