Arbitrage Calculator
Enter the best price for each outcome, from different sportsbooks, and the calculator tells you whether the market is an arbitrage, how much to stake on each side, and the profit you lock in.
| Outcome | Odds | Stake | Returns | Profit |
|---|
Example numbers are pre-filled. Replace them with the prices in front of you.
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How to use the arbitrage calculator
- Choose 2-way or 3-way. Use 2-way for moneylines with no draw, spreads, and totals. Use 3-way for soccer and hockey regulation markets that include a draw.
- Enter the best available odds for each outcome. Each price should come from a different sportsbook. Two sides at the same book will never be an arbitrage.
- Enter your total stake, or switch to Fixed stake on A if one book limits your bet.
- Check the verdict. If the combined implied probability is under 100%, the market is an arb.
Confirm both prices are still live before placing anything, then place the leg at the book most likely to move first. A half-placed arb is an open bet.
The math
Convert each price to decimal odds, then add up the implied probabilities:
Worked example
Book 1 has Team A at +115 (2.15). Book 2 has Team B at −105 (1.952). The implied probabilities are 46.51% and 51.22%, which add to 97.73%. That gap under 100% is your edge.
| Outcome | Odds | Stake | Returns |
|---|---|---|---|
| Team A at Book 1 | +115 | $475.91 | $1,023.21 |
| Team B at Book 2 | −105 | $524.09 | $1,023.22 |
On $1,000 total you lock in about $23.21, a 2.32% return, before any rounding.
Find arbs without refreshing twelve apps
ProfitDuel's Arb Matcher scans dozens of sportsbooks and thousands of events, flags live arbitrage opportunities, and sizes each stake for you.
Start the $1 ProfitDuel trialAffiliate link. The $1, 3-day trial applies to ProfitDuel's Starter plan as listed in September 2026. 21+ and in states where online sports betting is legal.Frequently asked questions
What is a good arbitrage percentage?
Most real US arbs sit between 0.5% and 3%. Anything above 5% deserves suspicion: it usually means a stale line, a palpable error the book may void, or two markets with different settlement rules.
Why does the profit change when I round stakes?
Rounding moves each stake away from the exact split, so the outcomes no longer pay the same. The calculator shows the worst case across outcomes as your guaranteed profit. Rounding to $5 on a $1,000 arb usually costs a few dollars and makes your bets look far less like arbitrage.
When should I use a fixed stake on outcome A?
Use it when one sportsbook caps your bet. Enter the maximum the book will accept on outcome A, and the calculator sizes the other legs around it.
Can I arb with odds in different formats?
Yes. Each odds box accepts American (+150), decimal (2.50), or fractional (3/2) odds, so you can mix formats from different books.