{
  "id": "gfr-calculator",
  "version": "2.0.0",
  "name": "GFR Calculator",
  "shortName": "eGFR",
  "description": "Estimate race-free kidney filtration with the 2021 CKD-EPI creatinine equation for adults or the CKiD U25 creatinine equation for ages 1–25.",
  "category": "Health & Fitness",
  "categorySlug": "health-fitness",
  "keywords": [
    "eGFR",
    "glomerular filtration rate",
    "CKD-EPI 2021",
    "CKiD U25",
    "kidney function",
    "race-free equation"
  ],
  "status": "live",
  "workStatus": "pending",
  "reviewStatus": "pending",
  "migrationStatus": "migrated",
  "migratedDate": "2026-08-25",
  "engine": "native",
  "creator": null,
  "reviewer": null,
  "quality": {
    "availability": "live",
    "technicalReviewRecord": "/reviews/gfr-calculator.json",
    "qualifiedReview": "pending",
    "qualifiedReviewer": null,
    "qualifiedReviewDate": null,
    "formulaVersion": "2.0.0",
    "referenceCoverage": "references-listed",
    "releaseTestScope": "Catalog and regression checks are not a professional formula audit; consult release evidence.",
    "historicalMetadataDate": "2026-08-25",
    "historicalMetadataNotice": "The imported date is not evidence of a completed human review."
  },
  "notice": "eGFR is an estimate, not a diagnosis. Kidney assessment depends on trends, albuminuria, clinical context, and appropriately standardized laboratory measurements.",
  "urls": {
    "page": "/calculator/gfr-calculator/",
    "definition": "/calculator/gfr-calculator/definition.json",
    "schema": "/calculator/gfr-calculator/schema.json",
    "llms": "/calculator/gfr-calculator/llms.txt",
    "legacyDefinition": "/calculator/gfr-calculator.json"
  },
  "queryExample": "https://askcalculators.com/calculator/gfr-calculator/?ageGroup=adult&age=50&sex=male&creatinineUnit=mgdl&creatinine=1",
  "queryParameters": {
    "ageGroup": {
      "label": "Equation population",
      "type": "select",
      "required": true,
      "default": "adult"
    },
    "age": {
      "label": "Age",
      "type": "number",
      "required": true,
      "default": 50
    },
    "sex": {
      "label": "Sex used by equation",
      "type": "select",
      "required": true,
      "default": "male"
    },
    "creatinineUnit": {
      "label": "Serum creatinine unit",
      "type": "select",
      "required": true,
      "default": "mgdl"
    },
    "creatinine": {
      "label": "Serum creatinine",
      "type": "number",
      "required": true,
      "default": 1
    },
    "heightCm": {
      "label": "Height for CKiD U25",
      "type": "number",
      "required": true,
      "default": 140,
      "showWhen": {
        "field": "ageGroup",
        "equals": "pediatric"
      }
    }
  },
  "inputs": [
    {
      "id": "ageGroup",
      "label": "Equation population",
      "type": "select",
      "required": true,
      "defaultValue": "adult",
      "options": [
        {
          "label": "Adult age 18 or older: 2021 CKD-EPI creatinine",
          "value": "adult"
        },
        {
          "label": "Age 1–25: CKiD U25 creatinine",
          "value": "pediatric"
        }
      ],
      "width": "full"
    },
    {
      "id": "age",
      "label": "Age",
      "type": "number",
      "required": true,
      "defaultValue": 50,
      "min": 1,
      "max": 120,
      "step": 0.1,
      "suffix": "years",
      "width": "half"
    },
    {
      "id": "sex",
      "label": "Sex used by equation",
      "type": "select",
      "required": true,
      "defaultValue": "male",
      "options": [
        {
          "label": "Male",
          "value": "male"
        },
        {
          "label": "Female",
          "value": "female"
        }
      ],
      "width": "half"
    },
    {
      "id": "creatinineUnit",
      "label": "Serum creatinine unit",
      "type": "select",
      "required": true,
      "defaultValue": "mgdl",
      "options": [
        {
          "label": "mg/dL",
          "value": "mgdl"
        },
        {
          "label": "µmol/L",
          "value": "umol"
        }
      ],
      "width": "half"
    },
    {
      "id": "creatinine",
      "label": "Serum creatinine",
      "type": "number",
      "required": true,
      "defaultValue": 1,
      "min": 0.05,
      "max": 3000,
      "step": 0.01,
      "width": "half"
    },
    {
      "id": "heightCm",
      "label": "Height for CKiD U25",
      "type": "number",
      "required": true,
      "defaultValue": 140,
      "min": 40,
      "max": 250,
      "step": 0.1,
      "suffix": "cm",
      "showWhen": {
        "field": "ageGroup",
        "equals": "pediatric"
      },
      "width": "full"
    }
  ],
  "outputs": [
    {
      "id": "egfr",
      "label": "Estimated GFR",
      "format": "number",
      "primary": true,
      "digits": 1,
      "suffix": " mL/min/1.73 m²"
    },
    {
      "id": "category",
      "label": "GFR category",
      "format": "text"
    },
    {
      "id": "equation",
      "label": "Equation used",
      "format": "text"
    },
    {
      "id": "creatinineMgDl",
      "label": "Creatinine used",
      "format": "number",
      "digits": 3,
      "suffix": " mg/dL"
    },
    {
      "id": "interpretation",
      "label": "Interpretation note",
      "format": "text"
    }
  ],
  "formula": {
    "expression": "Adult 2021 CKD-EPI: 142×min(SCr/κ,1)^α×max(SCr/κ,1)^−1.200×0.9938^age×1.012 if female; CKiD U25: κ(age,sex)×height(m)/SCr."
  },
  "examples": [
    {
      "label": "Reproducible default-input example (not a personal recommendation)",
      "inputs": {
        "ageGroup": "adult",
        "age": 50,
        "sex": "male",
        "creatinineUnit": "mgdl",
        "creatinine": 1,
        "heightCm": 140
      }
    }
  ],
  "sources": [
    {
      "label": "Calculator.net reference calculator",
      "url": "https://www.calculator.net/gfr-calculator.html"
    },
    {
      "label": "NIDDK adult eGFR equations",
      "url": "https://www.niddk.nih.gov/research-funding/research-programs/kidney-clinical-research-epidemiology/laboratory/glomerular-filtration-rate-equations/adults"
    },
    {
      "label": "NIDDK pediatric and young-adult eGFR equations",
      "url": "https://www.niddk.nih.gov/research-funding/research-programs/kidney-clinical-research-epidemiology/laboratory/glomerular-filtration-rate-equations/children-adolescents-young-adults"
    }
  ]
}