{
  "slug": "betting-unit-size-calculator",
  "title": "Betting Unit Size Calculator",
  "heading": "Betting Unit Size Calculator",
  "category": "math",
  "url": "https://www.revenuelab.fyi/toolbox/betting-unit-size-calculator",
  "summary": "Turn your bankroll into a consistent flat unit size for disciplined staking.",
  "description": "Flat unit staking means betting the same percentage of your bankroll on every wager (adjusted for confidence tier) rather than picking arbitrary dollar amounts that drift with recent wins or losses. Most disciplined bettors define a 'unit' as 1-2% of total bankroll, then size individual bets in units (a 1-unit play, a 2-unit 'best bet', etc.) instead of dollar figures, which keeps sizing proportional as the bankroll grows or shrinks. This calculator converts your bankroll and chosen unit percentage into a dollar unit size, then shows what 0.5, 1, 2, and 3-unit bets look like so you can size a specific wager by confidence level without recalculating percentages every time. It also flags when your unit size is aggressive relative to standard bankroll management guidance (generally under 5% per unit) so you can catch oversized bets before they turn one bad week into a serious bankroll hit.",
  "formula": "Unit size = bankroll × unit percentage. Bet size at confidence tier = unit size × number of units for that tier.",
  "dateModified": "2026-09-30",
  "run_url": "https://www.revenuelab.fyi/api/public/calc?tool=betting-unit-size-calculator",
  "inputs": [
    {
      "id": "bankroll",
      "label": "Total betting bankroll",
      "kind": "number",
      "hint": null,
      "default": 2000,
      "unit": "$",
      "min": 0,
      "max": null
    },
    {
      "id": "unitPercent",
      "label": "Unit size as % of bankroll",
      "kind": "number",
      "hint": null,
      "default": 1.5,
      "unit": "%",
      "min": 0.1,
      "max": 10
    }
  ],
  "outputs": [
    {
      "id": "unit",
      "label": "1-unit bet size",
      "format": "currency",
      "hint": null,
      "primary": true
    },
    {
      "id": "halfUnit",
      "label": "0.5-unit bet size",
      "format": "currency",
      "hint": null,
      "primary": false
    },
    {
      "id": "twoUnit",
      "label": "2-unit bet size",
      "format": "currency",
      "hint": null,
      "primary": false
    },
    {
      "id": "threeUnit",
      "label": "3-unit bet size",
      "format": "currency",
      "hint": null,
      "primary": false
    }
  ],
  "worked_example": {
    "inputs": [
      "Total betting bankroll: 2000 $",
      "Unit size as % of bankroll: 1.5 %"
    ],
    "outputs": [
      "1-unit bet size: $30.00",
      "0.5-unit bet size: $15.00",
      "2-unit bet size: $60.00",
      "3-unit bet size: $90.00"
    ]
  },
  "how_to": {
    "title": "How to use this",
    "steps": [
      "Enter total betting bankroll ($).",
      "Enter unit size as % of bankroll (%).",
      "Read your 1-unit bet size 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": {
        "bankroll": 1200,
        "unitPercent": 0.8999999999999999
      }
    },
    {
      "name": "Typical",
      "description": "Defaults — the most common real-world setup.",
      "values": {
        "bankroll": 2000,
        "unitPercent": 1.5
      }
    },
    {
      "name": "Ambitious",
      "description": "Higher-end numbers — what if things really pop?",
      "values": {
        "bankroll": 3200,
        "unitPercent": 2.4000000000000004
      }
    }
  ],
  "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 unit percentage do most disciplined bettors use?",
      "a": "1-2% of total bankroll per unit is the most commonly recommended range in bankroll management guides, with 'max bet' plays rarely exceeding 3-5 units even on high-confidence spots. Going much above 5% per single bet meaningfully raises risk of ruin even with a real edge, as shown by standard gambler's-ruin modeling."
    },
    {
      "q": "Should I resize my unit after a winning or losing streak?",
      "a": "Recalculating unit size off your current bankroll periodically (weekly or monthly, not after every single bet) keeps sizing proportional without letting a hot streak tempt you into oversized bets or a cold streak force you into unit sizes so small they don't matter. Constant recalculation after every bet, called 'variable unit sizing tied to a shrinking bankroll,' can also accelerate losses in a bad streak if not capped."
    },
    {
      "q": "Is flat unit sizing better than Kelly-based sizing?",
      "a": "Flat sizing is simpler and more forgiving of probability-estimate errors, since it doesn't require a precise edge input the way Kelly sizing does. Kelly sizing can theoretically grow a bankroll faster with a genuinely known edge, but it's also more sensitive to overestimating that edge. Many bettors use flat units specifically because it's harder to blow up from a bad probability estimate."
    }
  ],
  "related": [
    "https://www.revenuelab.fyi/toolbox/risk-of-ruin-bankroll-calculator",
    "https://www.revenuelab.fyi/toolbox/expected-value-bet-calculator",
    "https://www.revenuelab.fyi/toolbox/breakeven-win-rate-calculator"
  ],
  "license": "CC-BY-4.0",
  "citation": "RevenueLab — Betting Unit Size Calculator (https://www.revenuelab.fyi/toolbox/betting-unit-size-calculator)"
}