{
  "id": "horse-racing",
  "version": "952e13d7213a",
  "status": "published",
  "name": "Horse Racing Calculator",
  "question": "What does my horse racing bet pay?",
  "summary": "Works out what a horse racing bet pays at odds such as 5-2: the return and profit for a win or each-way bet, the $2 payout and the chance the odds imply.",
  "category": "game",
  "subcategory": "betting",
  "url": "https://www.acalculator.org/game/horse-racing-calculator",
  "markdown": "https://www.acalculator.org/game/horse-racing-calculator.md",
  "kind": "function",
  "method": "odds = a ÷ b; win return = stake × (odds + 1); each way: two stakes, the place part pays stake × (odds ÷ 4 or 5 + 1) when the horse wins or places; $2 payout = 2 × (odds + 1); implied chance = b ÷ (a + b).",
  "assumptions": [
    "Fixed odds: the price when you bet is the price paid. Pari-mutuel (tote) payouts change until the race starts.",
    "A win-only bet that places pays nothing.",
    "No dead heats, rule 4 deductions or betting tax."
  ],
  "inputs": {
    "$schema": "https://json-schema.org/draft/2020-12/schema",
    "type": "object",
    "properties": {
      "a": {
        "title": "Odds",
        "description": "The first number of the odds: 5 in 5-2.",
        "type": "integer",
        "minimum": 1,
        "maximum": 100000
      },
      "b": {
        "title": "Odds to",
        "description": "The second number of the odds: 2 in 5-2 (1 for odds such as 8-1).",
        "type": "integer",
        "minimum": 1,
        "maximum": 100000
      },
      "stake": {
        "title": "Stake",
        "description": "The amount bet; for each way, the amount on each of the two parts.",
        "type": "number",
        "x-unit": "USD",
        "exclusiveMinimum": 0,
        "maximum": 1000000000
      },
      "bet": {
        "title": "Bet",
        "description": "A win bet, or an each-way bet (one bet to win and one to place).",
        "type": "string",
        "enum": [
          "win",
          "ew"
        ]
      },
      "terms": {
        "title": "Place terms",
        "description": "The share of the odds the place part pays.",
        "type": "string",
        "enum": [
          "4",
          "5"
        ]
      },
      "res": {
        "title": "Result",
        "description": "Whether the horse won, placed (each way only) or lost.",
        "type": "string",
        "enum": [
          "won",
          "placed",
          "lost"
        ]
      }
    }
  },
  "outputs": {
    "returns": {
      "label": "Total return",
      "description": "Everything paid back, stake included.",
      "format": "money"
    },
    "profit": {
      "label": "Profit",
      "description": "Total return − total stake.",
      "format": "money"
    },
    "total": {
      "label": "Total stake",
      "description": "The stake, or twice the stake for each way.",
      "format": "money"
    },
    "twoDollar": {
      "label": "$2 win payout",
      "description": "What a $2 win bet pays back at these odds: 2 × (a ÷ b + 1).",
      "format": "money"
    },
    "decimal": {
      "label": "Decimal odds",
      "description": "a ÷ b + 1: the return for each 1 staked on a win.",
      "format": "number"
    },
    "implied": {
      "label": "Implied chance",
      "description": "b ÷ (a + b): the chance of winning the odds imply.",
      "format": "percent"
    }
  },
  "defaultAnswer": {
    "inputs": {
      "a": 5,
      "b": 2,
      "stake": 10,
      "bet": "win",
      "terms": "4",
      "res": "won"
    },
    "outputs": {
      "returns": 35,
      "profit": 25,
      "total": 10,
      "twoDollar": 7,
      "decimal": 3.5,
      "implied": 28.571428571428573
    },
    "text": "A $10.00 bet at 5-2 returns $35.00, a profit of $25.00."
  },
  "examples": [
    {
      "given": {
        "a": 5,
        "b": 2,
        "stake": 10,
        "bet": "win",
        "res": "won"
      },
      "expect": {
        "returns": 35,
        "profit": 25,
        "total": 10,
        "twoDollar": 7,
        "decimal": 3.5,
        "implied": 28.571428571428573
      },
      "source": "hand calculation in content.mdx: 10 × (2.5 + 1); Wikipedia, Fixed-odds betting (fractional odds a/b: a profit of a for every b staked, the stake returned on a win), https://en.wikipedia.org/wiki/Fixed-odds_betting (retrieved 2026-10-05)"
    },
    {
      "given": {
        "a": 10,
        "b": 1,
        "stake": 10,
        "bet": "ew",
        "terms": "4",
        "res": "won"
      },
      "expect": {
        "returns": 145,
        "profit": 125,
        "total": 20
      },
      "source": "hand calculation in content.mdx: 10 × 11 + 10 × (2.5 + 1); Wikipedia, Glossary of bets offered by UK bookmakers: each way (two bets of equal stake, win and place; the place part pays a fraction, often 1/4 or 1/5, of the win odds), https://en.wikipedia.org/wiki/Glossary_of_bets_offered_by_UK_bookmakers#Each_Way (retrieved 2026-10-05)"
    },
    {
      "given": {
        "a": 10,
        "b": 1,
        "stake": 10,
        "bet": "ew",
        "terms": "5",
        "res": "placed"
      },
      "expect": {
        "returns": 30,
        "profit": 10,
        "total": 20
      },
      "source": "hand calculation in content.mdx: 10 × (10 ÷ 5 + 1); Wikipedia, Glossary of bets offered by UK bookmakers: each way (two bets of equal stake, win and place; the place part pays a fraction, often 1/4 or 1/5, of the win odds), https://en.wikipedia.org/wiki/Glossary_of_bets_offered_by_UK_bookmakers#Each_Way (retrieved 2026-10-05)"
    },
    {
      "given": {
        "a": 9,
        "b": 2,
        "stake": 2,
        "bet": "win",
        "res": "lost"
      },
      "expect": {
        "returns": 0,
        "profit": -2,
        "twoDollar": 11,
        "implied": 18.181818181818183
      },
      "source": "hand calculation in content.mdx: 2 × (4.5 + 1) = 11; Wikipedia, Fixed-odds betting (fractional odds a/b: a profit of a for every b staked, the stake returned on a win), https://en.wikipedia.org/wiki/Fixed-odds_betting (retrieved 2026-10-05)"
    }
  ],
  "sources": [
    "Wikipedia, Fixed-odds betting: fractional odds and the return of the stake. https://en.wikipedia.org/wiki/Fixed-odds_betting (retrieved 2026-10-05)",
    "Wikipedia, Glossary of bets offered by UK bookmakers: each way. https://en.wikipedia.org/wiki/Glossary_of_bets_offered_by_UK_bookmakers#Each_Way (retrieved 2026-10-05)"
  ],
  "related": [
    "betting-odds",
    "odds",
    "parlay"
  ],
  "changelog": []
}