DraftKings · Side A · +110 · Stake
FanDuel · Side B · -100 · Stake
What is arbitrage betting?
Arbitrage betting (also called arbing) is placing bets on every outcome of a market at different sportsbooks when the combined implied probability drops below 100%. When two books disagree enough on a price, you split your stake across both sides and the total return exceeds your total stake whichever result hits. That is a positive theoretical worst-case payout, not free winnings: it holds only if both legs are accepted at the shown prices, neither is limited or voided, and both books settle the market under the same rules.
How does arbitrage betting work?
Every price has an implied probability (100 divided by the decimal odds). Add the implied probabilities of both sides of a market. If the total is under 100%, there is an arb: the books have left a gap. This calculator turns that gap into exact stakes, sizing each side so the payout is identical whichever result hits. The amount your total return exceeds your total stake is your profit - the theoretical worst case if both legs are accepted at the shown prices and settlement rules match.
How to calculate an arbitrage bet
- Convert both prices to decimal odds, then to implied probability (100 / decimal odds).
- Add the two implied probabilities. Under 100% means a profitable arb exists.
- Stake on each side = total stake x (that side's implied probability / the total). The tool does this instantly.
- Your profit either way = total return minus total stake. ROI is that profit over your stake.
Is arbitrage betting legal?
Yes, arbitrage betting is legal everywhere sports betting is legal. You are just placing two normal bets. The real risk is not the law, it is the books: sportsbooks dislike arbitrage and can limit or restrict accounts they flag for it. To last, bettors keep bet sizes natural, mix in regular bets, and spread action across books rather than hammering arbs at one shop.
The Wise Guy Team way
Arbs are real but small, fleeting, and account-limiting if you abuse them. We treat them as one signal among many. The bigger, more durable edge is +EV betting on prices the market has wrong, and shopping every book for the best number. Our tools scan for arbs, middles, and +EV at once so you see everything live.
Frequently asked questions
What is arbitrage betting?
Betting every outcome of a market at different books so the combined implied probability is under 100%, producing the same positive return whichever side wins - provided both legs are accepted at the shown prices and the books settle the market the same way.
How does arbitrage betting work?
When two books' implied probabilities add up to less than 100%, you split your stake across both sides so the payout is identical either way and exceeds what you risked.
How do you calculate an arbitrage bet?
Convert both prices to implied probability, add them, and if under 100% stake each side proportionally. Stake = total x (side implied / total implied).
Is arbitrage betting legal?
Yes, it is legal wherever betting is legal. The catch is that sportsbooks can limit or restrict accounts they suspect of arbing.
Can you get banned for arbitrage betting?
You will not be banned legally, but books can cut your limits or close the account. Natural bet sizes and spreading action across books reduces the risk.
Can you lose money arbitrage betting?
If both legs land correctly, no. Losses come from mistakes: a line moving before your second bet, a voided leg, or a wrong stake. Place both sides fast and double-check.
21+. For entertainment and educational purposes, not financial advice. If gambling stops being fun, take a break. 1-800-GAMBLER.