Free bet conversion calculator
Enter your free bet and the prices to back and lay it. We work out the expected value of the free bet, the optimal lay stake, the profit you lock in either way, and how much of the bonus bet you actually keep.
Set commission to 0 if you are hedging at another sportsbook rather than laying on an exchange.
- Lay stake
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- Lay liability
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- Guaranteed profit
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- Conversion rate
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| Outcome | At the sportsbook | At the exchange | Net profit |
|---|---|---|---|
| Selection wins | — | — | — |
| Selection loses | — | — | — |
The free bet stake is not returned, so the sportsbook only pays the winnings when the selection wins. The lay stake is sized so your net profit is the same either way — that equal figure is your guaranteed profit.
How free bet conversion works
A free (bonus) bet is only worth what you can extract from it, and because the stake is not returned, betting it straight leaves the value to chance. Conversion removes the variance: you back the selection with the free bet at the sportsbook, then lay the same selection on an exchange (or hedge it at a second book). One side always wins, so you collect a fixed amount whichever way the event goes.
The optimal lay stake equalises your return across both outcomes. For a free bet where the stake is not returned, that stake is the free bet amount times (back odds − 1), divided by (lay odds − commission). The guaranteed profit is the lay winnings after commission — and dividing it by the free bet amount gives the conversion rate, the share of the bonus bet you keep as cash. Pair this with the hedge calculator for cash bets, and read the full free bets guide for where to get them.
Frequently asked questions
- How does free bet conversion work?
- You place the free (bonus) bet on a selection at the sportsbook, then bet against that same selection — by laying it on a betting exchange or hedging it at another book. Whichever way the event settles, you collect a similar amount, turning a one-shot bonus bet into a near-guaranteed cash profit. Because the free bet stake is not returned, the maths differs from a normal cash hedge, which is what this calculator handles.
- Why is a free bet worth less than its face value?
- When you stake a free bet, the stake is consumed — you keep only the net winnings. A $100 free bet at +100 returns $100 profit, not $200, so it behaves like roughly 60–80% of its dollar value depending on the odds. Converting it locks in that retained value as cash. The "conversion rate" this calculator shows is the share of the free bet you keep.
- What odds give the best free bet conversion?
- Higher back odds retain more value, because the stake-not-returned penalty shrinks relative to the winnings. Free bets convert best in the +300 to +800 range where the lay odds are still close to the back odds. Very short odds waste most of the free bet, and very long odds can be hard to lay cheaply.
- Is converting a free bet legal?
- Laying or hedging your own bets is legal for the bettor, but most sportsbooks’ promotion terms discourage or restrict bonus-bet arbitrage, and a book may limit or close accounts it believes are gaming offers. This tool is for educational purposes — understand each operator’s terms before you act.
For informational purposes only. Not betting or financial advice. Bonus-bet conversion may breach some operators' promotion terms. Please gamble responsibly. 21+ where applicable.