Free Bet Calculator
A $100 bonus bet is not worth $100. This works out what it is actually worth, and where to use it.
The face value the book credited you.
Longer prices convert a bonus bet better. That is the central fact about them.
Leave blank to use the price's own implied chance.
Assumes a stake-not-returned bonus bet — the standard kind. You keep the profit and the book keeps the stake. If your promotion returns the stake it is simply cash, and the bet payout calculator is the right tool.
Expected cash value
$66.67
66.7% of face value. A bonus bet is never worth its face amount, because the stake does not come back — the whole game is converting as much of it as possible into real money. Using the price’s implied chance, which includes the book’s margin and therefore understates this slightly.
- Cash profit if it wins
- $200.00
- Cash lost if it loses
- $0.00
- Conversion rate
- 66.7%
- Probability used
- 33.33% (implied)
- Equivalent cash bet
- $66.67 at +200
Nothing. The stake was never your money, which is why a losing bonus bet costs you nothing at all.
Expected cash as a share of face value. Typically 60–75% at sensible prices.
A bonus bet at this price is worth about as much as this in real money.
| Price | Profit if it wins | Implied chance | Expected cash | Conversion |
|---|---|---|---|---|
| -200 | $50.00 | 66.7% | $33.33 | 33.3% |
| -110 | $90.91 | 52.4% | $47.62 | 47.6% |
| +100 | $100.00 | 50.0% | $50.00 | 50.0% |
| +200 | $200.00 | 33.3% | $66.67 | 66.7% |
| +400 | $400.00 | 20.0% | $80.00 | 80.0% |
| +800 | $800.00 | 11.1% | $88.89 | 88.9% |
| +1500 | $1,500.00 | 6.3% | $93.75 | 93.8% |
At the price’s own implied chance, conversion rises as the price lengthens: the stake you forfeit is a fixed cost, and a longer price wins a bigger multiple of it. That is why the standard advice is to use bonus bets on longshots — though the variance is correspondingly worse, and one bonus bet at +1500 usually returns nothing.
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What is a free bet or bonus bet?
A free bet — bonus bet, bet credit, whatever the book calls it — is a promotional stake that is not returned when it wins. You keep the profit; the stake stays with the sportsbook.
That is why a $100 free bet is not worth $100. Used at +200 it pays $200 rather than the $300 a cash bet would return, and it pays nothing at all when it loses.
It also means longer prices convert better. The forfeited stake is a fixed cost, so the longer the price, the larger the multiple of it you win — which is why the standard advice is to spend bonus bets on underdogs.
How it works
A bonus bet — free bet, bet credit, whatever the book calls it — is almost always stake not returned. If it wins you collect the profit; the stake stays with the book. If it loses you have lost nothing, because the stake was never your money.
That asymmetry is the whole thing. A $100 bonus bet at +200 pays $200 profit rather than the $300 total a cash bet would return. And a losing bonus bet costs zero, which is why the loss branch is worth nothing rather than −$100.
The consequence is that longer prices convert better. The stake you forfeit is a fixed cost regardless of the price, so the longer the price, the bigger the multiple of that cost you win when it lands. At −200 a bonus bet converts to about half its face value; at +800 it is closer to 89%. That is why the standard advice is to use bonus bets on longshots.
The standard advice comes with a caveat worth stating. Higher conversion means higher variance, and a single bonus bet at +1500 returns nothing about fifteen times out of sixteen. If you receive bonus bets regularly the long-price strategy is clearly right over time; if this is your only one, the expected value is not the only thing you care about.
The other route is hedging, which trades conversion rate for certainty. Backing the opposite side with real money turns a bonus bet into guaranteed cash at typically 60–75% of face value — that is the bonus bet conversion calculator.
The formula
cash profit if it wins = amount × (decimal − 1) cash loss if it loses = 0 expected cash value = p × amount × (decimal − 1) conversion rate = expected value / amount at the price's own implied chance (p = 1/D): conversion = (D − 1) / D = 1 − 1/D −200 → 50.0% +100 → 50.0% +200 → 66.7% +800 → 88.9%
The loss branch is worth exactly zero, not −stake. That single difference is what makes a bonus bet behave unlike any cash wager.
A worked example
A $100 bonus bet used at +200. If it wins you collect $200 in cash — not $300, because the $100 stake stays with the book.
At the price’s implied 33.3% chance, the expected cash value is 0.333 × $200 = $66.67, a conversion rate of 66.7%.
Use the same bonus bet at −200 instead and it wins $50 profit two-thirds of the time — an expected value of $33.33, or 50% conversion. Same bonus, half the value, purely from where it was used.
At +800 the expected value climbs to $88.89. It also returns nothing eight times in nine, which is the trade being made.
Common questions
- Why is a $100 free bet not worth $100?
- Because the stake is not returned. You collect only the profit, so a $100 bonus bet at even money pays $100 rather than the $200 a cash bet would return — and it only pays at all when it wins.
- What odds should I use a bonus bet at?
- Longer ones, if you get bonus bets regularly. The forfeited stake is a fixed cost, so a longer price wins a larger multiple of it — conversion rises from 50% at even money to nearly 90% at +800. The cost is much higher variance.
- Should I hedge my bonus bet instead?
- If you want certainty, yes. Backing the other side with cash converts a bonus bet into guaranteed money at typically 60–75% of face value. You give up the higher expected value of the long-price approach for a result you can count on.
- What if my promotion returns the stake?
- Then it is not a bonus bet — it is cash, and worth its full face value. Use the bet payout calculator. Read the terms, because books use the same language for both and the difference is substantial.
- Do bonus bets expire or have odds restrictions?
- Usually both. Most carry a minimum price (commonly −200 or shorter is excluded) and expire within days. Those restrictions often cap how much of the theoretical value you can actually capture.
The guide behind this calculator
Related calculators
- Bonus Bet ConversionHedge a bonus bet into guaranteed cash, and at what rate.
- Odds Boost CalculatorWhat a profit boost is actually worth — it lifts the profit, not the stake.
- Expected Value (EV) CalculatorWhat a bet is worth on average, given a price and your own probability.
- Bet Payout CalculatorProfit, total return and the win rate a price needs to break even.
For informational and analytical purposes only. These tools do not predict outcomes and do not recommend wagers.