⚖️ Arbitrage · 2 to 4 outcomes
Surebet Calculator
Check whether odds from different bookmakers form a surebet and how to split your stake for a guaranteed profit. Works for two-way and three-way markets.
Arbitrage Calculator
Enter the best odds for every outcome. The calculator splits your stake so you win the same whichever outcome lands.
📊 How often is there a surebet? Our own data
Bookmaker margins and price differences in our own odds data.
| Market | Avg margin | Lowest · highest | Best prices | Surebets |
|---|---|---|---|---|
| 1X2 | 6.7% | Pinnacle 4.8% · Unibet 8.0% | 3.7% | 1.8% |
| Over/Under 2.5 | 5.8% | Pinnacle 4.6% · Unibet 8.1% | 3.9% | 0.7% |
| BTTS | 8.1% | Bet365 7.5% · Unibet 9.0% | 6.7% | 0.2% |
What this shows: a single bookmaker never offers a surebet: on 1X2 their prices add up to about 106.7%, so you pay the margin on every outcome. Only by taking the best price for each outcome from different bookmakers does the total sometimes drop below 100%. In our odds data that happened on 1.8% of matches, 98 times in 5,474 matches, for an average profit of 2.2%. Surebets exist, but they are rare, small and usually gone within minutes, which is why speed and limits matter more than the calculator.
Method: the latest pre-match price per bookmaker for 5,474 matches since 3 July 2026. Margin = sum of 1 divided by each price, minus 100%. "Best prices" = margin when taking the best price per outcome across bookmakers; "Surebets" = share of matches where that dropped below zero.
What is a surebet?
A surebet, or arbitrage bet, appears when bookmakers disagree enough that the best odds for every outcome add up to less than 100% implied probability. If you back every outcome with the right stakes, you make a profit whichever outcome lands.
Add up 1 divided by each odds. Below 1.00 (100%) it is a surebet; the further below, the bigger the profit.
Worked example
Tennis match, Player A at 2.10 with one bookmaker and Player B at 2.05 with another. 1 / 2.10 + 1 / 2.05 = 0.964, so the market is 96.4%. With a total stake of 100:
| Outcome | Odds | Stake | Return |
|---|---|---|---|
| Player A | 2.10 | 49.40 | 103.73 |
| Player B | 2.05 | 50.60 | 103.73 |
Whoever wins, you get 103.73 back: a guaranteed profit of 3.73 (3.73%). In a football 1X2 market at 3.40, 3.60 and 2.60 the market is 95.65% and the profit 4.55%.
What to watch out for
- Odds move fast. Place the bet with the highest risk of changing first and check the calculator again before the second bet.
- Rules differ. Make sure both bookmakers settle the same way, for example on retirements in tennis or extra time in cup matches.
- Accounts get limited. Bookmakers can cut stakes on accounts that only bet arbitrage.
- Round your stakes. Odd amounts such as 49.40 stand out. Use the rounding option; the calculator shows what that costs.
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❓ FAQ
How do I know if odds are a surebet?
Add up 1 divided by the odds of every outcome. If the total is below 1 (100%), the odds form a surebet.
How are the stakes calculated?
Each stake is the total stake times (1 / odds) divided by the market total. That gives the same return on every outcome.
Is arbitrage betting legal?
Yes, it is simply betting on all outcomes. Bookmakers can still limit or close accounts that do it, so check their terms.
Can I fix the stake on one outcome?
Yes. Choose "Stake on" with the outcome number and the calculator works out the other stakes from that amount.
Is arbitrage betting legal?
Yes, backing every outcome at different bookmakers is legal. Bookmakers do not like it, though, and may limit accounts that only take their highest prices.
How often are there surebets?
Not often. In our own odds data across five bookmakers a 1X2 surebet existed on fewer than 2 in 100 matches, with an average profit of around 2%.