{
  "id": "creatinine-clearance",
  "version": "c73a889cbc45",
  "status": "published",
  "name": "Creatinine Clearance Calculator",
  "question": "What is my creatinine clearance?",
  "summary": "Estimates kidney function from serum creatinine with the 2021 CKD-EPI equation (eGFR), the MDRD Study equation, or Cockcroft-Gault creatinine clearance, with the KDIGO GFR category.",
  "category": "health",
  "subcategory": "clinical",
  "url": "https://www.acalculator.org/health/creatinine-clearance-calculator",
  "markdown": "https://www.acalculator.org/health/creatinine-clearance-calculator.md",
  "kind": "function",
  "method": "CKD-EPI 2021: 142 × min(Scr/κ, 1)^α × max(Scr/κ, 1)^−1.200 × 0.9938^age × 1.012 (women); MDRD: 175 × Scr^−1.154 × age^−0.203 × 0.742 (women) × 1.212 (Black); Cockcroft-Gault: (140 − age) × weight ÷ (72 × Scr) × 0.85 (women). Scr in mg/dL, weight in kg.",
  "assumptions": [
    "Creatinine is IDMS-standardized (the MDRD constant 175 assumes this). µmol/L is converted with the creatinine molar mass 113.12 g/mol (1 mg/dL = 88.40 µmol/L).",
    "CKD-EPI and MDRD give eGFR per 1.73 m² of body surface area. Cockcroft-Gault gives creatinine clearance in mL/min, with actual body weight unless you read the ideal or adjusted rows.",
    "The categories are the KDIGO 2012 GFR categories. A category of chronic kidney disease also needs the value to last 3 months or more.",
    "For adults 18 and older with stable creatinine."
  ],
  "inputs": {
    "$schema": "https://json-schema.org/draft/2020-12/schema",
    "type": "object",
    "properties": {
      "formula": {
        "title": "Formula",
        "description": "The equation: 2021 CKD-EPI (recommended), MDRD Study, or Cockcroft-Gault.",
        "type": "string",
        "enum": [
          "ckd-epi",
          "mdrd",
          "cockcroft-gault"
        ]
      },
      "scr": {
        "title": "Serum creatinine",
        "description": "Serum creatinine from the blood test (IDMS-standardized, as US labs report it).",
        "type": [
          "number",
          "string"
        ],
        "x-quantity": "concentration",
        "minimum": 0.001,
        "maximum": 0.3
      },
      "age": {
        "title": "Age",
        "description": "Age in whole years (adults, 18 and older).",
        "type": "integer",
        "minimum": 18,
        "maximum": 120
      },
      "sex": {
        "title": "Sex",
        "description": "Sex at birth, which the body formulas use.",
        "type": "string",
        "enum": [
          "male",
          "female"
        ]
      },
      "bodyWeight": {
        "title": "Weight",
        "description": "Body weight, which Cockcroft-Gault uses.",
        "type": [
          "number",
          "string"
        ],
        "x-quantity": "mass",
        "minimum": 20,
        "maximum": 320
      },
      "bodyHeight": {
        "title": "Height",
        "description": "Height, for the ideal-body-weight versions of Cockcroft-Gault. Optional.",
        "type": [
          "number",
          "string"
        ],
        "x-quantity": "length",
        "minimum": 1.2,
        "maximum": 2.5
      },
      "isBlack": {
        "title": "Black race (MDRD only)",
        "description": "The MDRD Study equation multiplies by 1.212 for Black patients. CKD-EPI 2021 does not use race.",
        "type": "boolean"
      }
    }
  },
  "outputs": {
    "gfr": {
      "label": "Kidney function",
      "description": "eGFR in mL/min/1.73 m² (CKD-EPI, MDRD), or creatinine clearance in mL/min (Cockcroft-Gault), with the KDIGO category.",
      "format": "number"
    },
    "measure": {
      "label": "What this number is",
      "description": "Which measure and unit the result is in.",
      "format": "text"
    },
    "stage": {
      "label": "KDIGO GFR category",
      "description": "The KDIGO 2012 GFR category (G1 to G5) for the result.",
      "format": "text"
    },
    "idealWeight": {
      "label": "Ideal body weight",
      "description": "Devine ideal body weight: 50 kg (men) or 45.5 kg (women) + 2.3 kg per inch over 5 feet.",
      "format": "quantity",
      "unit": "kg"
    },
    "crclIdeal": {
      "label": "Clearance with ideal weight",
      "description": "Cockcroft-Gault creatinine clearance using ideal body weight, mL/min.",
      "format": "number"
    },
    "crclAdjusted": {
      "label": "Clearance with adjusted weight",
      "description": "Cockcroft-Gault using adjusted body weight, ideal + 0.4 × (actual − ideal), mL/min. Often used when weight is over 120% of ideal.",
      "format": "number"
    }
  },
  "defaultAnswer": {
    "inputs": {
      "formula": "ckd-epi",
      "scr": 0.01,
      "age": 50,
      "sex": "male",
      "bodyWeight": 70,
      "bodyHeight": 1.7,
      "isBlack": false
    },
    "outputs": {
      "gfr": 91.6914786098333,
      "measure": "eGFR, mL/min/1.73 m²",
      "stage": "G1: normal or high"
    },
    "text": "With the 2021 CKD-EPI (recommended) formula, the result is 92 (eGFR, mL/min/1.73 m²), category G1: normal or high."
  },
  "examples": [
    {
      "given": {
        "formula": "ckd-epi",
        "scr": 0.01,
        "age": 50,
        "sex": "male"
      },
      "expect": {
        "gfr": 91.6914786098333,
        "stage": "G1: normal or high"
      },
      "source": "Inker et al. (2021) CKD-EPI: 142 × (1.0/0.9)^−1.200 × 0.9938^50 = 91.69 mL/min/1.73 m² (hand calculation in content.mdx)"
    },
    {
      "given": {
        "formula": "ckd-epi",
        "scr": 0.006,
        "age": 30,
        "sex": "female"
      },
      "expect": {
        "gfr": 123.75786412164246,
        "stage": "G1: normal or high"
      },
      "source": "Inker et al. (2021) CKD-EPI: 142 × (0.6/0.7)^−0.241 × 0.9938^30 × 1.012 = 123.76 (hand calculation in content.mdx)"
    },
    {
      "given": {
        "formula": "mdrd",
        "scr": 0.02,
        "age": 60,
        "sex": "female",
        "isBlack": false
      },
      "expect": {
        "gfr": 25.414913454768804,
        "stage": "G4: severely decreased"
      },
      "source": "Levey et al. (2006) MDRD: 175 × 2.0^−1.154 × 60^−0.203 × 0.742 = 25.41 (hand calculation in content.mdx)"
    },
    {
      "given": {
        "formula": "cockcroft-gault",
        "scr": 0.012,
        "age": 60,
        "sex": "female",
        "bodyWeight": 65,
        "bodyHeight": 1.65
      },
      "expect": {
        "gfr": 51.157407407407405,
        "idealWeight": 56.90944881889762,
        "crclIdeal": 44.7898439778361,
        "crclAdjusted": 47.336869349664624
      },
      "source": "Cockcroft and Gault (1976): (140 − 60) × 65 ÷ (72 × 1.2) × 0.85 = 51.16 mL/min; Devine ideal weight 45.5 + 2.3 × (64.961 − 60) in = 56.91 kg (hand calculation in content.mdx)"
    },
    {
      "given": {
        "formula": "ckd-epi",
        "scr": 0.014999712,
        "age": 70,
        "sex": "male"
      },
      "expect": {
        "gfr": 49.774776629156996,
        "stage": "G3a: mildly to moderately decreased"
      },
      "source": "Inker et al. (2021) CKD-EPI: 132.6 µmol/L × 113.12 g/mol = 1.49997 mg/dL; 142 × (1.49997/0.9)^−1.200 × 0.9938^70 = 49.77 (hand calculation in content.mdx)"
    }
  ],
  "sources": [
    "Inker LA, Eneanya ND, Coresh J, et al. New creatinine- and cystatin C-based equations to estimate GFR without race. N Engl J Med. 2021;385(19):1737-1749. https://doi.org/10.1056/NEJMoa2102953",
    "National Kidney Foundation, CKD-EPI Creatinine Equation (2021). https://www.kidney.org/ckd-epi-creatinine-equation-2021",
    "Levey AS, Coresh J, Greene T, et al. Using standardized serum creatinine values in the Modification of Diet in Renal Disease Study equation for estimating glomerular filtration rate. Ann Intern Med. 2006;145(4):247-254. https://doi.org/10.7326/0003-4819-145-4-200608150-00004",
    "Cockcroft DW, Gault MH. Prediction of creatinine clearance from serum creatinine. Nephron. 1976;16(1):31-41. https://doi.org/10.1159/000180580",
    "Devine BJ. Gentamicin therapy. Drug Intell Clin Pharm. 1974;8:650-655 (ideal body weight).",
    "Winter MA, Guhr KN, Berg GM. Impact of various body weights and serum creatinine concentrations on the bias and accuracy of the Cockcroft-Gault equation. Pharmacotherapy. 2012;32(7):604-612. https://doi.org/10.1002/j.1875-9114.2012.01098.x",
    "KDIGO 2012 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease. Kidney Int Suppl. 2013;3(1):1-150 (GFR categories G1 to G5)."
  ],
  "related": [],
  "changelog": [
    {
      "date": "2026-09-28",
      "note": "Weight and height default to kg and cm in both unit systems; no nested brackets in the answer."
    }
  ]
}