Arbitrage Calculator
Enter the best odds for each outcome, from any bookmakers, and how much you want to stake in total. The calculator splits the stake so every result pays the same, and shows whether there is a profit to lock in.
How the calculator works
Every set of odds implies a probability: 1 divided by the decimal odds. A bookmaker's own odds always add up to more than 100%, which is their margin. When the best odds from different bookmakers add up to less than 100%, betting on every outcome pays more than it costs, whatever happens.
stake on an outcome = total stake × its implied probability / sum of implied probabilities
payout (any outcome) = total stake / sum of implied probabilities
profit = payout − total stake
A worked example
A football match: the best odds are 2.10 for the home win at one bookmaker, 3.60 for the draw at another and 4.20 for the away win at a third. The implied probabilities are 47.62%, 27.78% and 23.81%, which add up to 99.21%.
With 1,000 to stake, the calculator puts 480 on the home win, 280 on the draw and 240 on the away win. Each of those pays 1,008 if it wins, so you finish 8 up whatever the result: a 0.80% return. These are the numbers the calculator above starts with.
What can go wrong
- The odds move before you place every bet. Place the leg most likely to change first, and recheck the rest.
- A bookmaker voids a bet or caps your stake, leaving the other bets uncovered.
- Accounts get limited: bookmakers restrict customers they see arbing regularly.
- A typo in the odds or stake. The calculator can only use the numbers you give it.
Frequently asked questions
How does the arbitrage calculator work out the stakes?
Each stake is the total stake times that outcome's implied probability (1 divided by its decimal odds), divided by the sum of all implied probabilities. That makes every outcome pay the same amount, so the result doesn't matter.
Can arbitrage betting lose money?
Yes, if something goes wrong between the calculation and the last bet: the odds move before every bet is placed, a bookmaker voids a bet or caps your stake, or a bet is placed at the wrong odds. The profit is only locked in once every bet is accepted at the odds you entered.
Which odds formats can I use?
Decimal (2.10), fractional (11/10 or evens) and American (+110 or -150). The calculator converts everything to decimal odds and shows them in the results.
Where do I find arbitrage opportunities?
By comparing the odds for the same match across many bookmakers until the implied probabilities add up to less than 100%. SureArb does this every day across 100+ bookmakers and emails the opportunities with suggested stakes.
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