Arbitrage (sure bet) calculator
Split your stake across outcomes to lock a guaranteed return.
When different bookmakers disagree enough about a market, backing every outcome can guarantee a profit. Enter the best odds for each outcome and your total stake; the calculator tells you whether the implied probabilities add up to less than 100% (an arb) and how to split the stake so every outcome returns the same.
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What it does
- 2-way and 3-way markets
- Per-outcome stakes that equalise your return
- Total implied probability and the bookmaker margin
- Clear yes/no on whether a guaranteed profit exists
How to use it
- 1Enter the odds. Add the best decimal odds for each outcome (two or three).
- 2Set your total stake. Type the total amount you want to stake across the market.
- 3Check the result. See the per-outcome stakes, the margin and whether it's a guaranteed profit.
What powers this
This calculator runs entirely in your browser. There's no account, no API key and no feed — nothing you type leaves the page. The maths is the same commodity matched-betting and value arithmetic used across the industry, implemented carefully and unit-tested.
Embed it on your site
Paste this where you want the arbitrage calculator to appear. The script auto-mounts every widget on the page; swap data-or-theme for light, dark or transparent.
<div data-or-widget="arbitrage" data-or-theme="light"></div>
<script src="https://oddsrelay.io/widgets/oddsrelay-widgets.js" async></script>Questions
- What makes a bet an arbitrage?
- An arbitrage exists when the implied probabilities of all outcomes add up to less than 100%. Backing every outcome in the right proportion then returns the same amount whichever wins, for a guaranteed profit.
- How are the stakes worked out?
- Each stake is proportional to its outcome's implied probability: stake = total × (1 ÷ odds) ÷ (sum of 1 ÷ odds). That equalises the return across every outcome.
- Why might the calculator say there's no arb?
- If the implied probabilities add up to 100% or more, the bookmaker margin wipes out any edge and backing all outcomes would lose. That's the normal case — true arbs are brief and uncommon.
18+ · Data product for licensed operators. Please gamble responsibly.
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