- Total to bet = wagering base x multiplier, divided by the game weighting
- Average cost = total to bet x (100% - RTP)
- Bonus-only beats deposit + bonus: the same multiplier on D+B doubles the bets on a 100% match
- Tables at 8% weighting need 12.5 times the bets of slots at 100%
How the calculation works
Every bonus comes with a playthrough: the amount you must bet before the bonus, and anything you win with it, becomes withdrawable. The calculator works it out in three steps.
1. The wagering base. The terms say whether the multiplier applies to the bonus only, or to your deposit plus the bonus. On a €100 deposit with a €100 bonus, the base is €100 or €200.
2. Total to bet. Base x multiplier, divided by the weighting of the games you play. At 35x on a €100 bonus, slots at 100% weighting need €3,500 in bets. Roulette at 8% weighting needs €3,500 / 0.08 = €43,750.
3. Average cost. Every bet loses a little on average: the house edge, which is 100% minus the game's RTP. At 96% RTP, €3,500 in bets costs about €140 on average. Subtract that from the bonus and you get the expected value: €100 - €140 = -€40.
🧮 How the multiplier eats a €100 bonus
Expected value of a €100 bonus as the wagering multiplier climbs.
Three worked examples
| Offer | Base | Total to bet | Average cost at 96% | Expected value |
|---|---|---|---|---|
| €100 bonus, 25x on the bonus | €100 | €2,500 | €100 | €0 |
| €100 bonus, 35x on the bonus | €100 | €3,500 | €140 | -€40 |
| €100 bonus, 30x on deposit + bonus (€100 deposit) | €200 | €6,000 | €240 | -€140 |
The third offer has a lower multiplier than the second and still costs far more, because the multiplier applies to twice the money. That's why our welcome bonus rankings sort on total bets, not on the multiplier.
Game weighting, in real terms
Casinos decide how much each game counts toward wagering. The pattern below comes from the published bonus terms of casinos on our list. Slots count in full, with exceptions; most table games count a fraction; some games don't count at all.
| Game type | Typical weighting | Bets needed per €100 of wagering |
|---|---|---|
| Most slots | 100% | €100 |
| NetEnt slots (some casinos) | 50% | €200 |
| Roulette, blackjack, video poker (some casinos) | 8% | €1,250 |
| Classic Blackjack (some casinos) | 2% | €5,000 |
| Baccarat, craps, progressive jackpots | Often 0% | Doesn't count |
Weightings vary by casino, so check the terms of the bonus you claim. Each of our casino reviews lists the weighting table where the casino publishes one.
🧮 Total bets to clear the welcome bonuses on our list
Total wagering needed on a €100 deposit (or the free cash), shortest first.
| BetVictor Casino | €2,000 |
|---|---|
| Videoslots | €3,500 |
| 20Bet | €4,000 |
| 888 Casino | €4,000 |
| GranaWin | €4,000 |
| Lemon Casino | €5,000 |
| 711 Casino | €6,000 |
| Bison Casino | €6,000 |
| Boho Casino | €6,000 |
| Fyrkka | €8,000 |
| Urho | €8,000 |
- Average €5,136
Tips before you claim
- Read the base first. "35x (B)" and "35x (D+B)" are very different offers.
- Clear on 100% games. Play the slots that count in full until the wagering is done.
- Check the RTP setting. Slots can run in more than one RTP version; the info screen shows which one you're on.
- Respect the max bet. Most bonuses cap your stake while wagering. One oversized bet can void the bonus.
- Watch the clock. A bonus you can't clear in time is worth nothing. More on that in our wagering requirements guide.
Bonuses are entertainment, not income, and averages hide big swings both ways. Set a deposit limit before you play, and see our responsible gambling page if it stops being fun.
FAQ
How do I calculate a wagering requirement?
Multiply the wagering base by the multiplier. If the terms say 35x the bonus and the bonus is €100, you must bet €3,500. If they say 35x deposit plus bonus on a €100 deposit and €100 bonus, you must bet €7,000.
What does game weighting do to wagering?
It divides how much each bet counts. At 100% (most slots) a €1 bet clears €1 of the requirement. At 8% (common for roulette and blackjack) the same bet clears €0.08, so the total you have to bet is 12.5 times higher.
What RTP should I use?
Use the RTP of the games you plan to play. Many online slots publish an RTP of around 96%, but games ship in several settings, so check the in-game info screen. A higher RTP lowers the average cost of clearing a bonus.
Why is the expected value often negative?
Because the average cost of the required bets can be bigger than the bonus. At 96% RTP, every €1,000 bet costs about €40 on average. A €100 bonus with 35x wagering needs €3,500 in bets, which costs about €140, so on average it returns less than it gives.
Is a negative expected value a reason to skip a bonus?
Not necessarily. Averages hide the swings: a bonus also buys a bigger balance and longer play, with a chance of a large win. The calculator shows the cost so you can decide with your eyes open - and so you can compare offers fairly.