{
  "id": "gdp-deflator",
  "version": "e65d02ba7537",
  "status": "published",
  "name": "GDP Deflator Calculator",
  "question": "What is the GDP deflator?",
  "summary": "Computes the GDP deflator from nominal and real GDP (nominal ÷ real × 100), or real or nominal GDP from the deflator, with the inflation rate between two years.",
  "category": "finance",
  "subcategory": "business",
  "url": "https://www.acalculator.org/finance/gdp-deflator-calculator",
  "markdown": "https://www.acalculator.org/finance/gdp-deflator-calculator.md",
  "kind": "function",
  "method": "Deflator = nominal GDP ÷ real GDP × 100; real GDP = nominal GDP ÷ (deflator ÷ 100); nominal GDP = real GDP × deflator ÷ 100; inflation = (deflator ÷ earlier deflator − 1) × 100.",
  "assumptions": [
    "The deflator is a price index with the base year = 100, as in the US national accounts.",
    "Nominal and real GDP are in the same unit; you type every number, and no data is looked up."
  ],
  "inputs": {
    "$schema": "https://json-schema.org/draft/2020-12/schema",
    "type": "object",
    "properties": {
      "find": {
        "title": "Find",
        "description": "Which of the three to work out from the other two.",
        "type": "string",
        "enum": [
          "deflator",
          "real",
          "nominal"
        ]
      },
      "nom": {
        "title": "Nominal GDP",
        "description": "GDP at the prices of its own year, in any unit (such as billions of dollars).",
        "type": "number",
        "minimum": 0.000001,
        "maximum": 1000000000000000
      },
      "real": {
        "title": "Real GDP",
        "description": "GDP at base-year prices, in the same unit as nominal GDP.",
        "type": "number",
        "minimum": 0.000001,
        "maximum": 1000000000000000
      },
      "defl": {
        "title": "GDP deflator",
        "description": "The GDP price index, with the base year = 100.",
        "type": "number",
        "minimum": 0.000001,
        "maximum": 1000000000000000
      },
      "prev": {
        "title": "Deflator in an earlier year",
        "description": "Optional: an earlier year’s deflator, to get the inflation rate between the two years.",
        "type": "number",
        "minimum": 0.000001,
        "maximum": 1000000000000000
      }
    }
  },
  "outputs": {
    "deflatorOut": {
      "label": "GDP deflator",
      "description": "Nominal GDP ÷ real GDP × 100.",
      "format": "number"
    },
    "realOut": {
      "label": "Real GDP",
      "description": "Nominal GDP ÷ (deflator ÷ 100), in the unit you typed.",
      "format": "number"
    },
    "nominalOut": {
      "label": "Nominal GDP",
      "description": "Real GDP × deflator ÷ 100, in the unit you typed.",
      "format": "number"
    },
    "priceChange": {
      "label": "Price level change since the base year",
      "description": "Deflator − 100: the percent change in prices since the base year.",
      "format": "percent"
    },
    "inflation": {
      "label": "Inflation since the earlier year",
      "description": "(Deflator ÷ earlier deflator − 1) × 100.",
      "format": "percent"
    }
  },
  "defaultAnswer": {
    "inputs": {
      "find": "deflator",
      "nom": 18206,
      "real": 17388.7,
      "defl": 104.7
    },
    "outputs": {
      "deflatorOut": 104.70017885178305,
      "realOut": 17388.7,
      "nominalOut": 18206,
      "priceChange": 4.700178851783055
    },
    "text": "The GDP deflator is 104.7; real GDP is 17,388.7 and nominal GDP is 18,206."
  },
  "examples": [
    {
      "given": {
        "find": "deflator",
        "nom": 18206,
        "real": 17388.7
      },
      "expect": {
        "deflatorOut": 104.70017885178305,
        "priceChange": 4.7001788517830505
      },
      "source": "OpenStax, Principles of Macroeconomics 3e, §6.2, table of nominal GDP, deflator and real GDP (2015: nominal GDP $18,206.0 billion, deflator 104.7, real GDP $17,388.7 billion); deflator = nominal ÷ real × 100; https://openstax.org/books/principles-macroeconomics-3e/pages/6-2-adjusting-nominal-values-to-real-values",
      "tolerance": 1e-12
    },
    {
      "given": {
        "find": "real",
        "nom": 542.4,
        "defl": 16.6
      },
      "expect": {
        "realOut": 3267.4698795180725
      },
      "source": "OpenStax, Principles of Macroeconomics 3e, §6.2 (1960: $542.4 billion ÷ (16.6 ÷ 100) = $3,267.5 billion); https://openstax.org/books/principles-macroeconomics-3e/pages/6-2-adjusting-nominal-values-to-real-values"
    },
    {
      "given": {
        "find": "nominal",
        "real": 16254,
        "defl": 100
      },
      "expect": {
        "nominalOut": 16254,
        "priceChange": 0
      },
      "source": "OpenStax, Principles of Macroeconomics 3e, §6.2 (2012 base year: $16,254 billion nominal and real); https://openstax.org/books/principles-macroeconomics-3e/pages/6-2-adjusting-nominal-values-to-real-values"
    },
    {
      "given": {
        "find": "deflator",
        "nom": 20893.7,
        "real": 18392.3,
        "prev": 104.7
      },
      "expect": {
        "deflatorOut": 113.60025662913284,
        "inflation": 8.500722663928206
      },
      "source": "OpenStax, Principles of Macroeconomics 3e, §6.2, table of nominal GDP, deflator and real GDP (2020: nominal $20,893.7 billion, real $18,392.3 billion, deflator 113.6; 2015 deflator 104.7); hand calculation in content.mdx; https://openstax.org/books/principles-macroeconomics-3e/pages/6-2-adjusting-nominal-values-to-real-values",
      "tolerance": 1e-12
    }
  ],
  "sources": [
    "OpenStax. Principles of Macroeconomics 3e, §6.2 Adjusting Nominal Values to Real Values (deflator = nominal ÷ real × 100; table of US nominal GDP, deflator and real GDP, 1960 to 2020, base year 2012), retrieved 2026-10-18. https://openstax.org/books/principles-macroeconomics-3e/pages/6-2-adjusting-nominal-values-to-real-values"
  ],
  "related": [
    "gdp",
    "inflation",
    "growth-rate",
    "labor-force-participation-rate"
  ],
  "changelog": []
}