Bonus Bet Calculator

Enter the bonus the bookmaker credited you, the price you plan to put it on, and the price available on the opposite outcome at a second book. The calculator returns the cash stake that makes both outcomes pay the same.

Long odds on the bonus and short odds on the hedge convert best. That's because the bonus only ever pays its winnings — the larger the winnings relative to the bonus, the more of it survives the hedge. Most punters treat anything above 70 cents in the dollar as a good conversion.

A bonus bet of B at decimal odds d₁ returns B × (d₁ − 1) if it wins — the stake isn't returned with it. To make both outcomes equal, the cash hedge at odds d₂ is:

hedge = B × (d₁ − 1) ÷ d₂

The guaranteed profit is then hedge × (d₂ − 1), and the conversion rate is that profit divided by the bonus.

You're given a $100 bonus bet. You put it on a $4.00 shot, and the opposite result is $1.36 at another book.

The bonus would return $300 in winnings, so the hedge is $300 ÷ 1.36 = $220.59 of your own cash. If the bonus wins you collect $300 and lose the $220.59 hedge, keeping $79.41. If the hedge wins it returns $300 for a $220.59 outlay — the same $79.41.

Either way you've turned a $100 bonus into about $79 cash, a 79% conversion.