Sports Betting Bonus: Understanding Wagering and the Real Value
Minimum odds, rollover, deadlines and excluded markets: how to turn a "€100 bonus" into an expected value figure — with a worked example.
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A betting bonus is not a gift, it is a contract with a turnover requirement. Whether it is worth taking can be calculated before you deposit.
The five terms that matter. (1) Rollover: how often the bonus (or bonus plus deposit) must be turned over. (2) Minimum odds: bets below that price do not count. (3) Deadline: typically 7 to 30 days. (4) Excluded markets: often system bets, cashed-out bets or both sides of the same event. (5) Maximum stake per bet during wagering.
The expected value formula. Expected value = bonus amount − (turnover × bookmaker margin). Turnover is rollover × base amount. Margin on standard markets is usually 4% to 7%.
Worked example. €100 bonus, 5x rollover on bonus plus deposit = 5 × €200 = €1,000 turnover. At a 5% margin the expected cost is €50, so net expected value is €100 − €50 = €50. At 10x rollover it becomes €100 − €100 = €0 — the bonus is exactly worthless, and anything beyond that is negative.
Why minimum odds matter so much. A 2.00 minimum pushes you into higher-variance and usually higher-margin markets. At 1.50 you could turn over with less risk; at 2.00 the chance of losing the bonus balance before completing wagering rises sharply.
Free bets are different. A free bet returns only the net win, not the stake. The real value of a €10 free bet is therefore typically 65–75% of face value. The exact maths is in free bets explained.
Do not forget tax. Germany charges 5.3% betting tax on stakes, which many operators pass on in full or in part. That shifts every bonus calculation downwards — see sports betting tax.
Run the numbers yourself. Our bonus calculator turns bonus size, rollover, base and margin into an expected value. For stake sizing, the Kelly calculator does the rest.
Bottom line. Rule of thumb: up to 5x on the bonus is usually positive, 5x on bonus plus deposit is marginal, and anything from 10x is mathematically worthless. Doing the maths first saves you from clearing offers that were negative from the start.