{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://askcalculators.com/calculator/rule-of-72-calculator/schema.json",
  "title": "Rule of 72 Calculator inputs",
  "description": "Estimate doubling time and compare it with the exact compound-growth result.",
  "type": "object",
  "properties": {
    "annualRate": {
      "title": "Annual growth rate",
      "type": "number",
      "default": 8,
      "minimum": 0.01,
      "maximum": 100,
      "x-step": 0.1,
      "x-unit": "percent",
      "x-control": "slider-number"
    }
  },
  "required": [
    "annualRate"
  ],
  "additionalProperties": false,
  "x-askcalculators": {
    "version": "1.0.0",
    "calculatorUrl": "https://askcalculators.com/calculator/rule-of-72-calculator/",
    "queryExample": "https://askcalculators.com/calculator/rule-of-72-calculator/?annualRate=8",
    "migrationStatus": "new",
    "reviewStatus": "pending",
    "pageStatus": "live",
    "workStatus": "pending",
    "formula": {
      "expression": "Estimated doubling years = 72 ÷ annual rate",
      "note": "The exact result is ln(2) ÷ ln(1 + rate)."
    },
    "quality": {
      "availability": "live",
      "technicalReviewRecord": "/reviews/rule-of-72-calculator.json",
      "qualifiedReview": "pending",
      "qualifiedReviewer": null,
      "qualifiedReviewDate": null,
      "formulaVersion": "1.0.0",
      "referenceCoverage": "references-pending",
      "releaseTestScope": "Catalog and regression checks are not a professional formula audit; consult release evidence.",
      "historicalMetadataDate": "2026-08-18",
      "historicalMetadataNotice": "The imported date is not evidence of a completed human review."
    },
    "outputs": {
      "ruleOf72Years": {
        "title": "Rule of 72 doubling time",
        "type": "number",
        "x-format": "number",
        "x-suffix": " years",
        "x-digits": 2,
        "x-primary": true
      },
      "exactYears": {
        "title": "Exact doubling time",
        "type": "number",
        "x-format": "number",
        "x-suffix": " years",
        "x-digits": 2
      },
      "difference": {
        "title": "Approximation difference",
        "type": "number",
        "x-format": "number",
        "x-suffix": " years",
        "x-digits": 2
      }
    }
  }
}