{
  "slug": "buy-points-cost-calculator",
  "title": "Buy Points Cost Calculator",
  "heading": "Buy Points (Spread Adjustment) Cost Calculator",
  "category": "math",
  "url": "https://www.revenuelab.fyi/toolbox/buy-points-cost-calculator",
  "summary": "See if paying extra odds to move a point spread is worth it.",
  "description": "Sportsbooks let you 'buy' points off a spread — moving a -7 favorite to -6.5, for example — in exchange for worse odds, typically an extra 10-25 cents of vig per half-point depending on which key number you're crossing. Buying off a key number like 3 or 7 in the NFL is usually considered worthwhile because those margins occur unusually often as final scores; buying a non-key number, like moving -9.5 to -9, usually is not, because the incremental win-probability gain is small relative to the extra cost. This calculator takes your original and bought-up odds along with your stake, then shows the break-even win-rate difference required to justify the extra cost, so you can compare it against how often that specific point actually shows up as the final margin in historical data (a number this tool doesn't have — you'll need to bring that from a key-number chart or your own research).",
  "formula": "Break-even win rate at each price = |odds| ÷ (|odds| + 100) for negative American odds. Cost of buying = difference in break-even win rate between original and bought line.",
  "dateModified": "2026-09-30",
  "run_url": "https://www.revenuelab.fyi/api/public/calc?tool=buy-points-cost-calculator",
  "inputs": [
    {
      "id": "originalOdds",
      "label": "Original odds (American)",
      "kind": "number",
      "hint": null,
      "default": -110,
      "unit": null,
      "min": null,
      "max": null
    },
    {
      "id": "boughtOdds",
      "label": "Odds after buying points",
      "kind": "number",
      "hint": null,
      "default": -130,
      "unit": null,
      "min": null,
      "max": null
    },
    {
      "id": "stake",
      "label": "Stake",
      "kind": "number",
      "hint": null,
      "default": 100,
      "unit": "$",
      "min": 0,
      "max": null
    }
  ],
  "outputs": [
    {
      "id": "extraWinRateNeeded",
      "label": "Extra win-rate needed to justify buying",
      "format": "percent",
      "hint": null,
      "primary": true
    },
    {
      "id": "origBreakeven",
      "label": "Break-even at original line",
      "format": "percent",
      "hint": null,
      "primary": false
    },
    {
      "id": "boughtBreakeven",
      "label": "Break-even at bought line",
      "format": "percent",
      "hint": null,
      "primary": false
    },
    {
      "id": "profitDiff",
      "label": "Profit given up per win by buying",
      "format": "currency",
      "hint": null,
      "primary": false
    }
  ],
  "worked_example": {
    "inputs": [
      "Original odds (American): -110",
      "Odds after buying points: -130",
      "Stake: 100 $"
    ],
    "outputs": [
      "Extra win-rate needed to justify buying: 4.14%",
      "Break-even at original line: 52.38%",
      "Break-even at bought line: 56.52%",
      "Profit given up per win by buying: $13.99"
    ]
  },
  "how_to": {
    "title": "How to use this",
    "steps": [
      "Enter original odds (american).",
      "Enter odds after buying points.",
      "Enter stake ($).",
      "Read your extra win-rate needed to justify buying on the right — it updates as you type.",
      "Hit Share to keep the scenario or send it to someone."
    ]
  },
  "scenarios": [
    {
      "name": "Conservative",
      "description": "Lower-end numbers — what if things land soft?",
      "values": {
        "originalOdds": -65,
        "boughtOdds": -80,
        "stake": 60
      }
    },
    {
      "name": "Typical",
      "description": "Defaults — the most common real-world setup.",
      "values": {
        "originalOdds": -110,
        "boughtOdds": -130,
        "stake": 100
      }
    },
    {
      "name": "Ambitious",
      "description": "Higher-end numbers — what if things really pop?",
      "values": {
        "originalOdds": -175,
        "boughtOdds": -210,
        "stake": 160
      }
    }
  ],
  "limitations": [
    "Results are rounded for display; the underlying calculation keeps full precision.",
    "Very large or very small inputs may hit floating-point limits in the browser.",
    "Inputs outside the accepted range are clamped rather than rejected."
  ],
  "faq": [
    {
      "q": "What are the NFL's key numbers and why do they matter here?",
      "a": "3 and 7 are by far the most common final-score margins in the NFL because of how touchdowns, extra points, and field goals combine, followed by smaller bumps at 4, 6, 10, and 14. Buying a spread across 3 or 7 (say -7.5 to -6.5) captures disproportionately more win probability than buying an equivalent half point elsewhere, like -9.5 to -8.5, which crosses no key number."
    },
    {
      "q": "How do I know if the extra win-rate requirement is worth paying?",
      "a": "Compare the extra win-rate this calculator shows you need against a key-number margin distribution chart (widely available from betting research sites), which tells you the actual historical frequency of that specific final margin. If crossing the number historically adds more win probability than the extra cost requires, buying is a good value; if it adds less, you're paying for protection you don't need."
    },
    {
      "q": "Does buying points ever make sense outside the NFL?",
      "a": "It applies to any point-spread sport, but key-number effects are much weaker in sports with more continuous scoring distributions, like basketball, where win margins are more spread out and no single number dominates final margins the way 3 and 7 do in football. Buying points in the NBA is generally a worse value than doing so around NFL key numbers."
    }
  ],
  "related": [
    "https://www.revenuelab.fyi/toolbox/breakeven-win-rate-calculator",
    "https://www.revenuelab.fyi/toolbox/expected-value-bet-calculator",
    "https://www.revenuelab.fyi/toolbox/teaser-pleaser-calculator"
  ],
  "license": "CC-BY-4.0",
  "citation": "RevenueLab — Buy Points Cost Calculator (https://www.revenuelab.fyi/toolbox/buy-points-cost-calculator)"
}