How We Calculate Bonus EV
The exact expected-value method behind every ranking on this site, with worked examples for each bonus type.
Every ranking on this site is driven by one transparent formula. We publish it in full so you can check our working — and apply it yourself to any offer, anywhere.
The formula
The logic: to withdraw a bonus you must stake it the wagering multiple over. Each pound staked surrenders the house edge on average. So the cost of clearing a £100 bonus at 10x is roughly 10 × £100 × 4% = £40, leaving £60 of expected value. A larger headline with heavier wagering can therefore be worth less than a smaller, cleaner offer — which is the whole point.
What the formula does not capture
It is an average across many sessions, not a prediction of any single one; variance is large on high-volatility slots. It also cannot price in usability factors like expiry, max bet and payment options, so we adjust the final ranking for those qualitatively. And it assumes you can realistically complete the wagering — a bonus you cannot clear in time has an effective value of zero. For no-wagering offers the formula collapses to the headline, which is why wager-free bonuses rank so well.
Keep learning
This guide is part of our wider library. To go deeper, read how casino bonuses work, wagering requirements explained and are casino bonuses worth it. Every term you encounter is defined in plain English in our bonus glossary, and you can put the theory to work on our best casino bonuses ranking or the full side-by-side comparison.
Frequently Asked Questions
Is this guide specific to UK players?
Yes. Everything here reflects UK Gambling Commission rules as they stand in 2026, including the 2025–2026 changes to stake limits, wagering and bonus promotions. We only cover UKGC-licensed casinos.
How often is this guide updated?
We review our guides whenever the rules or market change, and the "updated" date at the top of the page reflects the most recent check. UK regulation has moved quickly, so we revisit the regulatory guides regularly.
Where can I apply what is in this guide?
Use it on our ranked comparisons, starting with best casino bonuses. To value any offer yourself, follow our expected-value method.
What does wagering requirement mean?
It is the number of times you must stake a bonus before winnings can be withdrawn. A £100 bonus at 10x means £1,000 of stakes. Slots usually count 100% towards it; table and live games far less. Full detail in our wagering guide.
Are casino bonuses worth claiming?
A well-chosen, low-wagering bonus shifts the maths slightly in your favour, but the house keeps its edge and a bonus is never reliable income. Treat it as added entertainment value. Our honest assessment works through the numbers.
Why do slots clear a bonus faster than table games?
Because of game weighting: slots usually count 100% towards wagering while roulette might count 10% and live blackjack nothing. The same requirement can take ten times longer on tables. See game weighting explained.
Do UK stake limits affect bonuses?
Yes, indirectly. Online slots are capped at £5 per spin for over-25s and £2 for 18–24s. Since slots are what most bonuses are cleared on, the caps influence how quickly you can put the required volume through. See our 2026 rules guide.
What is the safest way to claim a bonus?
Stick to UKGC-licensed casinos, use accurate details that match your ID, read the wagering and max-bet terms before depositing, and never claim a bonus you cannot clear within its expiry. Set a deposit limit first.
How do you stay independent?
We earn affiliate commission on sign-ups, but it never affects our rankings, which follow the published expected-value formula in our methodology. We only list licensed casinos and publish every correction we receive.
Where can I get help if I need it?
Free, confidential support is available from the National Gambling Helpline on 0808 8020 133, GamCare and BeGambleAware. You can self-exclude from UK online gambling at GAMSTOP.