{
  "id": "price-elasticity-of-supply",
  "version": "137a78b3bc7a",
  "status": "published",
  "name": "Price Elasticity of Supply Calculator",
  "question": "What is the price elasticity of supply?",
  "summary": "Finds the price elasticity of supply by the midpoint method from two prices and the quantities supplied at each, and says whether supply is elastic, inelastic or unit elastic.",
  "category": "finance",
  "subcategory": "business",
  "url": "https://www.acalculator.org/finance/price-elasticity-of-supply-calculator",
  "markdown": "https://www.acalculator.org/finance/price-elasticity-of-supply-calculator.md",
  "kind": "function",
  "method": "Elasticity = (% change in quantity supplied) ÷ (% change in price), where each % change = (new − old) ÷ ((new + old) ÷ 2) × 100 (the midpoint method), shown without its sign.",
  "assumptions": [
    "The midpoint (arc) method, so going from A to B gives the same elasticity as going from B to A.",
    "Everything else that affects supply stays the same between the two points.",
    "Prices are at least $0.01; quantities are 0 or more, not both 0."
  ],
  "inputs": {
    "$schema": "https://json-schema.org/draft/2020-12/schema",
    "type": "object",
    "properties": {
      "p1": {
        "title": "Starting price",
        "description": "The price before the change.",
        "type": "number",
        "x-unit": "USD",
        "minimum": 0.01,
        "maximum": 1000000000000
      },
      "q1": {
        "title": "Quantity supplied at the starting price",
        "description": "How many units sellers offer at the starting price.",
        "type": "number",
        "minimum": 0,
        "maximum": 1000000000000000
      },
      "p2": {
        "title": "New price",
        "description": "The price after the change.",
        "type": "number",
        "x-unit": "USD",
        "minimum": 0.01,
        "maximum": 1000000000000
      },
      "q2": {
        "title": "Quantity supplied at the new price",
        "description": "How many units sellers offer at the new price.",
        "type": "number",
        "minimum": 0,
        "maximum": 1000000000000000
      }
    }
  },
  "outputs": {
    "elasticity": {
      "label": "Price elasticity of supply",
      "description": "The size of % change in quantity supplied ÷ % change in price (midpoint method), without its sign.",
      "format": "number"
    },
    "kind": {
      "label": "Supply is",
      "description": "Elastic above 1, unit elastic at exactly 1, inelastic below 1, perfectly inelastic at 0.",
      "format": "text"
    },
    "signed": {
      "label": "Elasticity with its sign",
      "description": "% change in quantity supplied ÷ % change in price; negative when price and quantity move in opposite directions.",
      "format": "number"
    },
    "quantityChange": {
      "label": "% change in quantity supplied",
      "description": "(Q₂ − Q₁) ÷ ((Q₁ + Q₂) ÷ 2) × 100.",
      "format": "percent"
    },
    "priceChange": {
      "label": "% change in price",
      "description": "(P₂ − P₁) ÷ ((P₁ + P₂) ÷ 2) × 100.",
      "format": "percent"
    }
  },
  "defaultAnswer": {
    "inputs": {
      "p1": 650,
      "q1": 10000,
      "p2": 700,
      "q2": 13000
    },
    "outputs": {
      "elasticity": 3.5217391304347827,
      "kind": "elastic",
      "signed": 3.5217391304347827,
      "quantityChange": 26.08695652173913,
      "priceChange": 7.407407407407407
    },
    "text": "The price elasticity of supply is 3.52: supply is elastic."
  },
  "examples": [
    {
      "given": {
        "p1": 650,
        "q1": 10000,
        "p2": 700,
        "q2": 13000
      },
      "expect": {
        "elasticity": 3.5217391304347827,
        "kind": "elastic",
        "quantityChange": 26.08695652173913,
        "priceChange": 7.407407407407407
      },
      "source": "OpenStax, Principles of Economics 3e, section 5.1 Price Elasticity of Demand and Price Elasticity of Supply (midpoint method; from $650 and 10,000 units to $700 and 13,000 units: 26.1% ÷ 7.4% = 3.5, elastic; elastic above 1, unitary at 1, inelastic below 1), https://openstax.org/books/principles-economics-3e/pages/5-1-price-elasticity-of-demand-and-price-elasticity-of-supply (retrieved 2026-11-01) (26.1%, 7.4%, 3.5); Python 3 in docs/progress/WP-149/crosscheck.py"
    },
    {
      "given": {
        "p1": 10,
        "q1": 100,
        "p2": 12,
        "q2": 110
      },
      "expect": {
        "elasticity": 0.5238095238095238,
        "kind": "inelastic"
      },
      "source": "hand calculation in content.mdx; OpenStax, Principles of Economics 3e, section 5.1 Price Elasticity of Demand and Price Elasticity of Supply (midpoint method; from $650 and 10,000 units to $700 and 13,000 units: 26.1% ÷ 7.4% = 3.5, elastic; elastic above 1, unitary at 1, inelastic below 1), https://openstax.org/books/principles-economics-3e/pages/5-1-price-elasticity-of-demand-and-price-elasticity-of-supply (retrieved 2026-11-01)"
    },
    {
      "given": {
        "p1": 8,
        "q1": 100,
        "p2": 10,
        "q2": 125
      },
      "expect": {
        "elasticity": 1,
        "kind": "unit elastic"
      },
      "source": "hand calculation in content.mdx: both changes are 22.22%; OpenStax, Principles of Economics 3e, section 5.1 Price Elasticity of Demand and Price Elasticity of Supply (midpoint method; from $650 and 10,000 units to $700 and 13,000 units: 26.1% ÷ 7.4% = 3.5, elastic; elastic above 1, unitary at 1, inelastic below 1), https://openstax.org/books/principles-economics-3e/pages/5-1-price-elasticity-of-demand-and-price-elasticity-of-supply (retrieved 2026-11-01)"
    },
    {
      "given": {
        "p1": 3,
        "q1": 500,
        "p2": 4,
        "q2": 500
      },
      "expect": {
        "elasticity": 0,
        "kind": "perfectly inelastic"
      },
      "source": "hand calculation in content.mdx: no change in quantity; OpenStax, Principles of Economics 3e, section 5.1 Price Elasticity of Demand and Price Elasticity of Supply (midpoint method; from $650 and 10,000 units to $700 and 13,000 units: 26.1% ÷ 7.4% = 3.5, elastic; elastic above 1, unitary at 1, inelastic below 1), https://openstax.org/books/principles-economics-3e/pages/5-1-price-elasticity-of-demand-and-price-elasticity-of-supply (retrieved 2026-11-01)"
    },
    {
      "given": {
        "p1": 10,
        "q1": 100,
        "p2": 12,
        "q2": 90
      },
      "expect": {
        "elasticity": 0.5789473684210527,
        "signed": -0.5789473684210527,
        "kind": "inelastic"
      },
      "source": "hand calculation in content.mdx; OpenStax, Principles of Economics 3e, section 5.1 Price Elasticity of Demand and Price Elasticity of Supply (midpoint method; from $650 and 10,000 units to $700 and 13,000 units: 26.1% ÷ 7.4% = 3.5, elastic; elastic above 1, unitary at 1, inelastic below 1), https://openstax.org/books/principles-economics-3e/pages/5-1-price-elasticity-of-demand-and-price-elasticity-of-supply (retrieved 2026-11-01)"
    }
  ],
  "sources": [
    "OpenStax, Principles of Economics 3e, section 5.1 Price Elasticity of Demand and Price Elasticity of Supply (the midpoint method; from $650 and 10,000 units to $700 and 13,000 units: 26.1% ÷ 7.4% = 3.5, elastic; elastic above 1, unitary at 1, inelastic below 1). Retrieved 2026-11-01. https://openstax.org/books/principles-economics-3e/pages/5-1-price-elasticity-of-demand-and-price-elasticity-of-supply"
  ],
  "related": [
    "price-elasticity-of-demand",
    "cross-price-elasticity",
    "income-elasticity"
  ],
  "changelog": []
}