Calculator
Arbitrage Calculator
Enter odds for each leg in any format — American, Decimal, or Polymarket. Results update instantly. Lock a leg when a book caps your stake and every other leg scales proportionally so your profit % stays identical.
How the calculator works
- American odds
- +130 means bet $100 to win $130. -115 means bet $115 to win $100. Enter with + or − sign.
- Decimal odds
- Your total return per $1 staked, including stake. 2.30 = $1 bet returns $2.30. Always greater than 1.00.
- Polymarket price
- Probability between 0.00 and 1.00. Converts to decimal odds automatically (e.g. 0.43 = 2.326 decimal).
- Lock a leg
- When a book caps your stake, enter the cap and lock. All other legs scale down proportionally — profit % is unchanged.
- Rounding your stakes
- Stakes are shown to the exact cent. A suggested rounded amount appears below each stake — under $150 per leg it suggests the nearest $1, over $150 it suggests the nearest $5. Rounder numbers look less suspicious to books and the profit difference is usually small.