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Surebet & Arbitrage Calculator

Enter the best odds from each bookmaker and your total stake to get the exact stake per outcome for guaranteed, risk-free profit.

2-way: win/lose (e.g. tennis). 3-way: win/draw/lose (e.g. football).

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How It Works

What is a Surebet?

A surebet (or arbitrage bet) is a betting strategy that guarantees profit by exploiting differences in odds across multiple bookmakers. By betting on all possible outcomes, you ensure a profit regardless of the result.

Example: Bookmaker A offers 2.10 for Team X to win, while Bookmaker B offers 2.10 for Team Y to win. By betting on both, you guarantee profit.

How to Identify Surebets

A surebet exists when the sum of the inverse odds is less than 1:

(1 / Odds1) + (1 / Odds2) < 1.00

Example: Odds of 2.15 and 2.15 → (1/2.15) + (1/2.15) = 0.93 → Surebet.

Stake Calculation

The calculator distributes your total stake proportionally to guarantee equal profit on all outcomes:

Stake = (Total Stake / Sum of Inverse Odds) × (1 / Individual Odds)

Important Considerations

  • •Quick execution: Odds can change rapidly. Place all bets as quickly as possible.
  • •Account limits: Bookmakers may limit your account if they detect arbitrage betting.
  • •Rounding: Round your stakes appropriately. The calculator shows 2 decimal places.
  • •Commissions: Factor in any exchange commissions or fees when calculating.

Related Calculators

Matched Betting Calculator →

Calculate optimal lay stakes for guaranteed profits.

Dutching Calculator →

Split one stake across selections for equal profit on any winner.

Odds Converter →

Convert between decimal, fractional, and American odds.

Find Surebets Automatically

Our Oddsmatcher scans 20+ bookmakers in real-time and alerts you to profitable arbitrage opportunities instantly.

A surebet calculator checks whether the combined implied probability across odds from different bookmakers falls below 100%. When it does, an arbitrage opportunity exists and the calculator shows the exact stake for each outcome so the profit is the same no matter what happens.

Enter the decimal odds for each outcome from the best available bookmakers, set your total stake, and the calculator returns the stake per outcome, the arbitrage percentage, and your guaranteed profit.

How to Use the Surebet Calculator

  1. 1
    Select number of outcomes, 2-way (win/lose), 3-way (win/draw/lose), or more.
  2. 2
    Enter the best odds for each outcome, from different bookmakers. Example: Home win at 2.10 (Bet365), Away win at 2.05 (Betway).
  3. 3
    Enter your total stake, the combined amount you are prepared to bet across all outcomes.
  4. 4
    Check the result, if the arbitrage percentage is below 100%, place the recommended stake at each bookmaker immediately. Odds change fast.

The Surebet Formula: A Worked Example

You need to cover all outcomes at different bookmakers. To check for an arb, calculate the implied probability for each odds and sum them:

Implied probability formula

Implied probability = 1 ÷ Decimal odds

Example: 2-way match

Home win @ 2.10: 1 ÷ 2.10 = 47.6%

Away win @ 2.05: 1 ÷ 2.05 = 48.8%

Total = 47.6% + 48.8% = 96.4% → Arbitrage exists. Margin = 3.6%.

Stake per outcome

Stake for outcome = (Total stake × Implied prob) ÷ Total arb %

With €200 total: Home stake = (200 × 0.476) ÷ 0.964 = €98.75. Away stake = €101.25.

Guaranteed return: €98.75 × 2.10 = €207.38 or €101.25 × 2.05 = €207.56. Profit ≈ €7.45 regardless of result.

Common Mistakes That Turn Surebets Into Losses

  • ✕
    Odds change before you place all legs. Surebet windows can close in seconds. Place the less liquid leg first to avoid being half-exposed.
  • ✕
    Betting on different markets at each bookmaker. Both bookmakers must settle the same event under the same rules. Asian handicap at one and 1X2 at another is not a surebet.
  • ✕
    Ignoring withdrawal and deposit fees. A 2% arb margin disappears if your bookmaker charges a 2% withdrawal fee. Factor all costs before placing.
  • ✕
    Using maximum stake at one bookmaker repeatedly. Consistent maximum bets on arb opportunities is one of the fastest ways to get your account restricted or closed.

Frequently Asked Questions

Is arbitrage betting legal?

Yes, arbitrage betting is legal everywhere sports betting itself is legal. You are placing normal bets with different bookmakers, not exploiting any loophole in the law. The risk is contractual, not legal: bookmakers can still limit or close your account for arbitrage activity under their own terms of service.

How does a surebet work?

A surebet works by placing bets on every possible outcome of an event at different bookmakers, using odds where the combined implied probability falls below 100%. Because all outcomes are covered, one bet always wins, and the payout from that bet covers every stake plus a guaranteed profit.

How much can you make from surebets?

Surebet returns come from the margin, not a fixed income. Typical arbitrage margins run 1-5% of your total stake per opportunity: a 2% margin returns 2% of your stake as profit, guaranteed regardless of the result. Margins above 5% are rare and usually vanish within minutes as bookmakers move their odds.

Can you get banned for arbitrage betting?

Yes, bookmakers can and do restrict or close accounts that show consistent arbitrage patterns, since arbing carries no risk for the bettor and guarantees a loss for the book. Varying stakes, avoiding round numbers, and mixing in occasional recreational bets slows detection. A matched betting strategy alongside surebets reduces account exposure risk.

Can I use this calculator for 3-way markets?

Yes. Select 3 outcomes and enter the best odds for home win, draw, and away win from different bookmakers. The formula is the same: sum of implied probabilities must be below 100% for an arb to exist.

How is a surebet different from matched betting?

Arbitrage uses odds discrepancies between bookmakers. Matched betting uses bookmaker free bets and promotions, laying off risk on an exchange. Both guarantee profit but require different tools and account types.

Finding surebets manually across dozens of bookmakers is time-consuming. The Oddsmatcher scans for the best available odds automatically so you can focus on placing the bets.

Formula and worked examples reviewed by Erik Andersson. How we calculate.