Arbitrage Calculator
Split your total stake across outcomes to lock in equalized returns. Use decimal odds only.
Tip: A true arbitrage exists when combined implied probability is less than 100%.
What is sports betting arbitrage?
Sports betting arbitrage (often called an arb) is when you place bets on all outcomes of an event at different sportsbooks so that your return is nearly the same no matter what happens. If the combined implied probability is under 100%, you can create a theoretical guaranteed profit before limits, delays, or rule differences.
Example: if one bookmaker offers stronger odds on Team A and another offers stronger odds on Team B, a properly sized split can produce a positive edge regardless of the winner.
How this calculator works
This tool uses decimal odds and your total stake to calculate how much to bet on each side. It supports both 2-outcome and 3-outcome markets.
Core formulas
Implied probability = 1 / decimal odds
Arbitrage condition: (1/O1 + 1/O2 [+ 1/O3]) < 1
Stake on outcome i = Total Stake × [(1/Oi) / Sum of implied probabilities]
How to use the calculator
- Enter your total stake amount.
- Input decimal odds for each outcome.
- Enable the 3-outcome checkbox for markets like home/draw/away.
- Click Calculate Arbitrage.
- Review stake split, combined implied probability, and projected profit.
2-way vs 3-way markets
2-way markets
Common in tennis, basketball moneyline (including overtime), or many prop markets. You only need odds for two mutually exclusive outcomes.
3-way markets
Common in soccer regulation-time betting: Home win, Draw, Away win. Make sure your bets cover the exact same market rules (for example, regulation only vs. extra time included), otherwise the hedge may fail.
Common mistakes that can kill an arbitrage edge
- Mismatched market rules: one book includes overtime while another does not.
- Line movement: odds change before all legs are placed.
- Rounding issues: stake rounding to cents can slightly reduce guaranteed return.
- Bet limits: one leg may have a maximum stake lower than required.
- Promo constraints: bonus bets, cash-out rules, and void clauses may differ.
Practical execution checklist
- Confirm both sides are the same event, market, and settlement rules.
- Check max stake limits before submitting the first leg.
- Place both bets quickly to reduce line movement risk.
- Keep records of odds, stake, and sportsbook ticket IDs.
- Plan for account limits, verification delays, and withdrawal times.
Responsible use
Arbitrage is often lower variance than directional betting, but it still carries operational risk, account risk, and potential errors. Never stake money you cannot afford to lose, and comply with local laws and sportsbook terms of service.