A casino bonus is worth roughly the bonus amount minus the house edge on all the betting needed to clear it. On a 96% RTP slot that counts in full, a $100 bonus with a 15x playthrough costs about $60 to clear, so it is worth about $40 on average. Put any offer through the wagering requirement calculator and the “bonus minus expected cost” line gives you this figure.
The value formula
Expected cost = requirement ÷ contribution × (1 − RTP)
Value ≈ bonus − expected cost
It is an average across many players clearing the same offer, before two real-world effects covered below: running out of money partway, and the time the play takes.
Six common bonus shapes compared
All on a 96% RTP slot that counts 100%, at $1 a spin:
| Bonus | Playthrough | Total to bet | Expected cost | Value on average | Spins |
|---|---|---|---|---|---|
| $10 no-deposit credit | 1x on the bonus | $10 | $0.40 | $9.60 | 10 |
| $100 match on $100 | 15x on the bonus | $1,500 | $60 | $40 | 1,500 |
| $100 match on $100 | 15x on deposit plus bonus | $3,000 | $120 | minus $20 | 3,000 |
| $50 bonus | 30x on the bonus | $1,500 | $60 | minus $10 | 1,500 |
| $500 match on $500 | 25x on the bonus | $12,500 | $500 | $0 | 12,500 |
| $1,000 match on $1,000 | 15x on the bonus | $15,000 | $600 | $400 | 15,000 |
Two lessons come out of the table. First, the basis matters as much as the multiple: the same 15x is worth $40 or minus $20 depending on whether it applies to the deposit too. Second, a bigger bonus at the same multiple is worth more in dollars but asks for far more play. The $1,000 offer is worth $400 on average and needs 15,000 spins at $1, which is 25 hours at 10 spins a minute. Raising the bet to $5 cuts that to 3,000 spins, but each spin then risks five times as much of your deposit.
The break-even multiple
At a given RTP there is a multiple where the expected cost equals the bonus. On the bonus alone it is 1 ÷ (1 − RTP): 20x at 95%, 25x at 96%, about 33x at 97%. Below it, the bonus keeps value on average. Above it, clearing costs more than the bonus gives.
On deposit plus bonus with a 100% match, the break-even halves, because you bet twice as much for the same bonus: 12.5x at 96%.
What the formula misses
Running out of money. The formula assumes you can always keep betting. If your balance hits zero first, the attempt ends, and so does the house edge you were paying. For a no-deposit bonus this cuts both ways. Take a $20 no-deposit bonus at 30x on a 96% slot. On paper the play-through costs $24, more than the bonus. But none of your own money is at risk, so the worst case is ending with nothing. In 2,000 simulated attempts at $1 a spin on each of the calculator’s model slots:
| Model slot | Finished the play-through | Average cash at the end |
|---|---|---|
| Low volatility | 17% | about $11 |
| Medium volatility | 7% | about $16 |
| High volatility | 3% | about $19 |
The averages are positive because a free bonus cannot cost you anything, but the typical attempt ends at zero: more than four in five fail on every model. With a deposit bonus, the money that runs out first is often your own.
Time and deadlines. A value of $40 that takes 2 hours 30 minutes of play is a different deal from $400 that takes 25 hours inside a 7-day window. If the play is more than you would do anyway, count the extra hours as part of the price.
Terms the math cannot see. Excluded games, bet limits and the order your funds are used in can all change the result. The bonus rules the calculator cannot see lists them.
A quick decision rule
- Work out the value with the calculator, using the real basis, contribution and RTP.
- If it is negative, skip the bonus or treat it as paid entertainment with a known price.
- If it is positive, check the time figure against the expiry window and your own plans.
- Check that the deposit is money you are happy to lose, because the bonus does not protect it.
A bonus is a discount on play you were going to do. It is never a way to make slots pay.
Common questions
Should I always take a casino bonus?
No. Take one when the bonus minus its expected cost is positive, the play it needs fits your budget and the deadline, and you would have played that much anyway. A bonus that pushes you into extra hours of play you did not plan is a cost, not a saving.
What is a good wagering requirement?
It depends on the game's RTP. On a 96% RTP slot that counts in full, any playthrough on the bonus alone below 25x leaves some value on average, and the lower the better. At 1x almost the whole bonus survives.
Why does a bonus with negative value still pay out sometimes?
Because the value is an average across many players. Some will hit a big win and clear the requirement with money to spare, while most lose part or all of the balance. A negative average means the group as a whole pays more in house edge than the bonus gives back.