{
  "slug": "breakeven-win-rate-calculator",
  "title": "Break-Even Win Rate Calculator (-110 and Beyond)",
  "heading": "Break-Even Win Rate Calculator",
  "category": "math",
  "url": "https://www.revenuelab.fyi/toolbox/breakeven-win-rate-calculator",
  "summary": "The win percentage you need at any odds just to break even.",
  "description": "At standard -110 odds, most bettors assume they need to win 50% of bets to break even, but the vig means the real number is 52.38%. That 2.38-point gap is the entire reason casual sports betting is a losing proposition over time for the average bettor: you're not just betting against the other side, you're betting against the house's built-in cut on every wager. This calculator generalizes the math beyond -110 to any American odds, so you can see exactly what win rate a specific line requires before it turns a profit. It also shows how many units you'd need to win out of 100 bets at that price, translating an abstract percentage into a concrete record you can compare against your actual betting history. If you track your bets (and you should), this number is the benchmark: a win rate below the break-even threshold at your average odds means you're losing money regardless of how the highlight-reel wins felt.",
  "formula": "Break-even win rate = |American odds| ÷ (|American odds| + 100) for negative odds, or 100 ÷ (American odds + 100) for positive odds.",
  "dateModified": "2026-09-30",
  "run_url": "https://www.revenuelab.fyi/api/public/calc?tool=breakeven-win-rate-calculator",
  "inputs": [
    {
      "id": "odds",
      "label": "American odds",
      "kind": "number",
      "hint": null,
      "default": -110,
      "unit": null,
      "min": null,
      "max": null
    },
    {
      "id": "sampleSize",
      "label": "Bets to project",
      "kind": "number",
      "hint": null,
      "default": 100,
      "unit": null,
      "min": 1,
      "max": null
    }
  ],
  "outputs": [
    {
      "id": "breakeven",
      "label": "Break-even win rate",
      "format": "percent",
      "hint": null,
      "primary": true
    },
    {
      "id": "winsNeeded",
      "label": "Wins needed per sample",
      "format": "decimal",
      "hint": null,
      "primary": false
    },
    {
      "id": "losses",
      "label": "Losses allowed per sample",
      "format": "decimal",
      "hint": null,
      "primary": false
    },
    {
      "id": "roiAt55",
      "label": "ROI if you actually win 55%",
      "format": "percent",
      "hint": null,
      "primary": false
    }
  ],
  "worked_example": {
    "inputs": [
      "American odds: -110",
      "Bets to project: 100"
    ],
    "outputs": [
      "Break-even win rate: 52.38%",
      "Wins needed per sample: 52.4",
      "Losses allowed per sample: 47.6",
      "ROI if you actually win 55%: 5.0%"
    ]
  },
  "how_to": {
    "title": "How to use this",
    "steps": [
      "Enter american odds.",
      "Enter bets to project.",
      "Read your break-even win rate 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": {
        "odds": -65,
        "sampleSize": 60
      }
    },
    {
      "name": "Typical",
      "description": "Defaults — the most common real-world setup.",
      "values": {
        "odds": -110,
        "sampleSize": 100
      }
    },
    {
      "name": "Ambitious",
      "description": "Higher-end numbers — what if things really pop?",
      "values": {
        "odds": -175,
        "sampleSize": 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": "Why is break-even 52.38% instead of 50% at -110?",
      "a": "Because -110 means risking $110 to win $100, not an even $100-for-$100 bet. The extra $10 you have to risk relative to your potential win is the vig, and it shifts the true break-even point above a coin flip. Winning exactly half your -110 bets loses money steadily over time."
    },
    {
      "q": "What win rate do professional sports bettors actually achieve?",
      "a": "Widely-cited estimates for long-term winning bettors (against the spread, at standard vig) sit in the 53-55% range, and even the best documented handicappers rarely sustain much above 55-57% over large samples. This context matters: a 60%+ long-run win rate at standard odds is exceptionally rare, not typical of a 'good' bettor."
    },
    {
      "q": "Does the break-even rate change with plus-money odds?",
      "a": "Yes, and it drops as the underdog price gets bigger. At +150 you only need to win about 40% of the time to break even, because each win pays more than the stake. At +300, break-even drops to 25%. Longer odds require a lower win rate but higher variance in your results."
    },
    {
      "q": "How many bets do I need before my win rate is meaningful?",
      "a": "Standard deviation on binary outcomes means small samples are noisy — 20 or 50 bets can easily show a win rate several points off your true long-run rate purely by chance. Most serious bettors want at least several hundred bets, ideally over 1,000, before trusting a win-rate number as representative."
    }
  ],
  "related": [
    "https://www.revenuelab.fyi/toolbox/expected-value-bet-calculator",
    "https://www.revenuelab.fyi/toolbox/closing-line-value-calculator",
    "https://www.revenuelab.fyi/toolbox/risk-of-ruin-bankroll-calculator"
  ],
  "license": "CC-BY-4.0",
  "citation": "RevenueLab — Break-Even Win Rate Calculator (-110 and Beyond) (https://www.revenuelab.fyi/toolbox/breakeven-win-rate-calculator)"
}