Great Britain · 18+. Reviewed 5 October 2026. Examples are illustrations, not offers or predictions.
This calculator estimates theoretical turnover and expected loss from the inputs you choose. It does not estimate your chance of winning, the probability of going broke or whether you can afford to gamble. Pound sterling is the default display; changing the symbol does not convert currency.
Put the session
in perspective.
Change the inputs to see theoretical turnover and expected loss. These are long-term mathematical averages, not a forecast for your session.
Turnover × house edge
- Monthly budget
- £400
- Monthly turnover
- £1,200
- House edge
- 4%
The signal combines frequency, stake size and turnover using an illustrative rule. It is not a validated personal-risk assessment. Actual losses can exceed your budget; this calculator cannot make gambling safe.
The calculation you can check
Monthly turnover = average stake × bets per session × sessions per month.
House edge = 100% − RTP.
Theoretical monthly expected loss = turnover × house edge ÷ 100.
The budget input gives your monthly planned allocation and contributes to the illustrative exposure signal. It does not stop the assumed bets when a balance runs out. A £100 budget and £300 turnover are possible through repeated stakes, but the tool does not simulate whether that sequence can be completed.
Worked examples in pounds
| Assumptions | Monthly turnover | Expected loss |
|---|---|---|
| £2 × 150 bets × 4 sessions; RTP 96% | £1,200 | £48 |
| £1 × 100 bets × 4 sessions; RTP 96% | £400 | £16 |
| £2 × 150 bets × 4 sessions; RTP 94% | £1,200 | £72 |
The first example does not predict four losses of £12. One session can lose the available balance or produce a win. RTP describes long-run mathematics for the specific game and configuration, not a promised return to one player. The tool uses a fixed average stake and RTP; game decisions or changing stakes can alter the model.
What the exposure signal means
The label combines frequency, stake relative to the entered budget and turnover using a simple illustrative rule. It is not a validated assessment of addiction, financial vulnerability or personal safety. A low label does not mean gambling is safe. The calculator does not model volatility, bonus eligibility, time spent, bankroll exhaustion or a probability distribution of outcomes.
Use the inputs within their limits
Enter whole sessions and whole bets, a positive stake and a game RTP within the displayed range. Pence are supported. Invalid entries show a message and retain the last valid result; an old result should not be read as the answer to invalid inputs.
For GB online slots, the stake ceiling is £2 per game cycle for ages 18–24 and £5 for ages 25 and over. Those limits do not apply universally to roulette or blackjack. This general educational calculator has no age input and does not enforce product-specific legal limits.
Do not use a favourable result as a reason to increase play or chase losses. If gambling is causing harm, use the support links and controls on our responsible-gambling page.
Continue your checks
- Casino Bonus Guide: Wagering Math Explained
- Casino Glossary: Essential Gambling Terms Every Player Should Know
- Responsible Gambling Tools That Actually Matter
Sources and check date
Public documents checked on 5 October 2026. Rules and operator terms can change; use the linked original when making a decision.