Interactive Tool · Bonus Math
Enter a bonus offer and choose the game you plan to play. We pre-populate real published RTPs so you get the honest expected value in euros — not marketing spin.
18+ only. Illustrative first-order model — see assumptions below. Free support: BeGambleAware.org.
First-order EV model. This calculator uses the standard first-order bonus expected-value formula:
EV = bonus_amount − (W ÷ contribution%) × (1 − RTP)
Where W is the total wagering requirement: either WR × bonus (bonus-only basis) or WR × (deposit + bonus) (deposit+bonus basis), depending on the bonus terms.
What "real turnover" means. When a game's contribution to the wagering requirement is less than 100%, you must bet more real money to satisfy the same nominal requirement. If a game contributes 10%, a €3,500 WR requires €35,000 in actual bets. The expected cost of that wagering is real_turnover × (1 − RTP).
Max-cashout cap. If a max-cashout is specified, the formula caps the positive outcome: EV = min(bonus, max_cashout) − wagering_cost. This is still a first-order model — it assumes you either clear the WR or lose everything, not a full probability-weighted distribution. In practice, the first-order estimate is a reasonable approximation for most bonus comparisons.
What this model does NOT account for:
Named-game RTPs are approximate. The presets use publicly available published figures, typically the default RTP for the game. Many games ship in multiple certified RTP tiers — your casino may run a different version. Check in-game info or our RTP versions guide for details.
Sanity-check with the worked example: €100 deposit, €100 bonus, 35× on (deposit + bonus), 96% RTP, 100% contribution → W = 35 × 200 = €7,000, real turnover = €7,000 ÷ 100% = €7,000, wagering cost = €7,000 × 4% = €280, EV = €100 − €280 = −€180. Enter those values to confirm the tool outputs −€180.
The wagering requirement is the mechanism that extracts value from the bonus. The casino knows that requiring you to wager 35× a sum generates approximately 35 × amount × house_edge in expected revenue — designed to offset (and usually exceed) the cost of the bonus.
The key variables that determine whether a bonus is worth it: the WR multiplier (lower is better), whether the WR applies to bonus only vs deposit+bonus (bonus-only is significantly better), the RTP of the game you'll use (higher is better), and the game's contribution percentage (100% is best). A max-cashout cap also matters on potentially +EV offers — it puts a ceiling on what you can win.
Most bonuses in regulated markets are −EV for the player by design. The exceptions tend to be no-deposit bonuses (no downside), reload offers with low multipliers on high-RTP games, or cashback structures where the expected loss is partially reimbursed.
See also: Slot Session Simulator · How slot RTP works · Bonus buy explained · RTP vs house edge.
Most casino bonuses are negative expected value (−EV) for the player once you factor in the wagering requirement. A typical structure — €100 bonus at 35× on deposit+bonus — requires €7,000 in turnover. At 96% RTP that costs €280 in expected losses, making the true value of the "€100 bonus" equal to −€180. The tool above calculates this for your specific offer.
It means you must place total bets equal to 35 times a specified amount before withdrawing winnings. The critical question is: 35× what? Bonus-only basis (35× €100 = €3,500 total wagering) is considerably better than deposit+bonus basis (35× €200 = €7,000). Both are labelled "35×" — check the T&Cs for which applies.
Because the cost of the wagering exceeds the bonus face value. The expected wagering cost is total wagering ÷ contribution% × (1 − RTP). For a 35× deposit+bonus offer on €100 deposit at 96% RTP: €7,000 × 4% = €280 expected cost. That erases a €100 bonus entirely, leaving you −€180 in expected value.
Yes — significantly. Higher RTP reduces the per-unit cost of wagering. A 96% RTP game costs 4¢ per €1 wagered; an 88% RTP game costs 12¢ — three times more. Game contribution % also matters: a 10%-contribution game requires 10× the actual bets to satisfy the same nominal WR, multiplying the cost by a factor of 10. Always use the highest-RTP, 100%-contribution game the bonus allows.