A bonus is not free money with a delay attached. It is an obligation to put a specified amount of turnover through the games, and turnover costs money at a rate set by the house edge. This calculator converts the wagering requirement into that cost so the two numbers can be compared directly.
The arithmetic
wagering to clear = base amount × multiple
money staked = wagering to clear ÷ game contribution
expected loss = money staked × (1 − RTP)
rough value = bonus − expected loss
Work the default case by hand. A £50 bonus with 35× wagering on the bonus only requires £1,750 of turnover. On a slot contributing 100%, that means staking £1,750. At 96% RTP the house edge is 4%, so £1,750 of turnover is expected to cost £70. The bonus is £50. The playthrough is expected to cost £20 more than the bonus is worth, and it takes 8,750 spins — about fifteen hours at a brisk 600 spins an hour.
Change one setting to "deposit + bonus" and the base becomes £100, the turnover £3,500, and the expected cost £140 against a £50 bonus. That is the difference a single line of terms makes.
The terms that decide everything
Six numbers determine whether an offer is worth anything, and they are rarely presented together.
| Term | What to look for | Why it moves the answer |
|---|---|---|
| Wagering multiple | 20× to 50× is the usual band | Multiplies turnover directly |
| Applied to | Bonus only, or deposit plus bonus | Doubles the turnover on a 100% match |
| Game contribution | Slots often 100%; table games far less | A 10% contribution means ten times the staking |
| Maximum bet while wagering | Frequently a few pounds a spin | Caps how fast you can clear, extending exposure |
| Maximum conversion | A cap on winnings you can withdraw | Truncates the upside without touching the downside |
| Time limit | Commonly days rather than weeks | Forces a pace, which forces volume |
Game contribution is the one that quietly does the most damage. If roulette contributes 10% toward wagering, £1 staked counts as 10p cleared, so a £1,750 requirement needs £17,500 of actual turnover. Even at roulette's low 2.70% edge that is roughly £470 of expected loss. The low-edge games are excluded from bonus value precisely because they are low-edge.
Maximum conversion is the one people notice last. A cap that limits withdrawals from bonus play to, say, four times the bonus does not reduce your expected loss by a penny — the house edge is charged on every spin regardless — but it deletes the rare large outcome that was the only reason the average looked survivable. The calculator above deliberately ignores conversion caps, which means the figure it gives you is the optimistic one.
Why the maths usually comes out negative
There is a break-even multiple, and it is easy to find. Ignoring contribution weighting, a bonus-only requirement is worth taking on average when:
multiple × (1 − RTP) is less than 1
At 96% RTP that means the multiple has to be under 25 before the expected loss on the playthrough drops below the bonus. At 94% RTP the threshold falls to about 16.7. Most published requirements sit above those lines, which is not an accident: an offer priced to be positive for the average player would not survive contact with a spreadsheet.
This does not make bonuses fraudulent. It makes them a discount on entertainment rather than a source of income. If you were going to stake £1,750 anyway, a £50 bonus genuinely reduces the cost of doing so. If the bonus is the reason you are staking £1,750, it has cost you money to obtain.
Sticky, non-sticky and cashable
Terminology varies between operators, but the underlying structures do not:
A non-sticky bonus keeps your deposit and the bonus in separate balances and plays your own money first. If you win early you can often withdraw without touching the bonus at all, which is the most player-favourable structure that exists in this category.
A sticky bonus merges the funds and the bonus amount is never withdrawable — only winnings above it are. You cannot cash out mid-playthrough without forfeiting.
A cashable bonus becomes real money once wagering is complete, at which point the balance is yours.
Read which one you are being given before you deposit, because it changes whether the deposit itself is at risk during the playthrough. If you would like to see the same house edge working on ordinary play instead, the expected loss calculator does that without the bonus layer.
18+. No bonus alters the house edge, and no wagering requirement is cleared more cheaply by playing longer. Free, confidential support is available from the National Gambling Helpline on 0808 8020 133.