What is a welcome bonus really worth?
Casino welcome offers headline big numbers. The math after wagering is usually less generous. This calculator gives you the honest expected-loss figure for any deposit-match bonus — plug in the numbers from the operator's T&Cs and see what you'd actually keep on average.
- Required turnover
- £3500
- Expected loss during wagering
- £140
- House edge at this RTP
- 4.00%
How is this calculated?
Turnover= base amount × wagering multiplier. Base is just the bonus for “bonus only” wagering, or deposit + bonus for “deposit + bonus” wagering.
Expected loss= turnover × (1 − RTP). At 35× wagering on a 96% RTP slot, you'll hand back ~4% of every £1 turned over.
Real value = bonus − expected loss. This is a statistical expectation over many sessions — individual outcomes vary wildly.
Free spins use a different calculation (count × stake × RTP, with separate cap mechanics). Coming in v2.
Why the headline misleads
A '100% up to £500' welcome offer with 35× wagering on the bonus only sounds great. On a 96% RTP slot, you'll grind through £17,500 of turnover and lose around £700 to the house edge — more than the bonus itself.
What to look for
Lower wagering (10–20×), bonus-only (not deposit + bonus), high-RTP games eligible (96%+), generous max-bet cap during wagering (£5+), and long enough validity (30 days).
The honest options
A handful of UK casinos run no-wagering bonuses — small in amount but worth 100% of the headline. PlayOJO is the most-cited example. Lower headline, higher real value.
The calculation, in plain terms
- Find the wagering base. Most UK operators wager the bonus only; some wager deposit + bonus. Pick whichever matches the T&Cs.
- Multiply by the wagering requirement. That's how much turnover you have to put through eligible games before withdrawing.
- Apply the game's house edge. On a 96% RTP slot the house keeps 4% of every £1 wagered (long-run). Multiply your turnover by (1 − RTP) for the expected loss.
- Subtract from the bonus. What's left is the statistical expected value of taking the offer. Negative? The bonus is mathematically not worth claiming at that RTP.
This is an expectation, not a guarantee — variance means you can win or lose much more than the expected-loss figure in any single session. Over many sessions, the math is the math.