{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://askcalculators.com/calculator/gfr-calculator/schema.json",
  "title": "GFR Calculator inputs",
  "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.",
  "type": "object",
  "properties": {
    "ageGroup": {
      "title": "Equation population",
      "type": "string",
      "default": "adult",
      "enum": [
        "adult",
        "pediatric"
      ],
      "x-optionLabels": {
        "adult": "Adult age 18 or older: 2021 CKD-EPI creatinine",
        "pediatric": "Age 1–25: CKiD U25 creatinine"
      }
    },
    "age": {
      "title": "Age",
      "type": "number",
      "default": 50,
      "minimum": 1,
      "maximum": 120,
      "x-step": 0.1,
      "x-suffix": "years"
    },
    "sex": {
      "title": "Sex used by equation",
      "type": "string",
      "default": "male",
      "enum": [
        "male",
        "female"
      ],
      "x-optionLabels": {
        "male": "Male",
        "female": "Female"
      }
    },
    "creatinineUnit": {
      "title": "Serum creatinine unit",
      "type": "string",
      "default": "mgdl",
      "enum": [
        "mgdl",
        "umol"
      ],
      "x-optionLabels": {
        "mgdl": "mg/dL",
        "umol": "µmol/L"
      }
    },
    "creatinine": {
      "title": "Serum creatinine",
      "type": "number",
      "default": 1,
      "minimum": 0.05,
      "maximum": 3000,
      "x-step": 0.01
    },
    "heightCm": {
      "title": "Height for CKiD U25",
      "type": "number",
      "default": 140,
      "minimum": 40,
      "maximum": 250,
      "x-step": 0.1,
      "x-suffix": "cm",
      "x-showWhen": {
        "field": "ageGroup",
        "equals": "pediatric"
      }
    }
  },
  "required": [
    "ageGroup",
    "age",
    "sex",
    "creatinineUnit",
    "creatinine"
  ],
  "allOf": [
    {
      "if": {
        "properties": {
          "ageGroup": {
            "const": "pediatric"
          }
        },
        "required": [
          "ageGroup"
        ]
      },
      "then": {
        "required": [
          "heightCm"
        ]
      }
    }
  ],
  "additionalProperties": false,
  "x-askcalculators": {
    "version": "2.0.0",
    "calculatorUrl": "https://askcalculators.com/calculator/gfr-calculator/",
    "queryExample": "https://askcalculators.com/calculator/gfr-calculator/?ageGroup=adult&age=50&sex=male&creatinineUnit=mgdl&creatinine=1",
    "migrationStatus": "migrated",
    "reviewStatus": "pending",
    "pageStatus": "live",
    "workStatus": "pending",
    "migratedDate": "2026-08-25",
    "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."
    },
    "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."
    },
    "outputs": {
      "egfr": {
        "title": "Estimated GFR",
        "type": "number",
        "x-format": "number",
        "x-suffix": " mL/min/1.73 m²",
        "x-digits": 1,
        "x-primary": true
      },
      "category": {
        "title": "GFR category",
        "type": "string",
        "x-format": "text"
      },
      "equation": {
        "title": "Equation used",
        "type": "string",
        "x-format": "text"
      },
      "creatinineMgDl": {
        "title": "Creatinine used",
        "type": "number",
        "x-format": "number",
        "x-suffix": " mg/dL",
        "x-digits": 3
      },
      "interpretation": {
        "title": "Interpretation note",
        "type": "string",
        "x-format": "text"
      }
    }
  }
}