The Gambling Cost Calculator shows you the true mathematical cost of your gambling habit. Enter how much you bet per week, select your type of gambling, and your currency — and the calculator shows you the probability of being ahead at 1, 5 and 10 years, the total money you will have gambled over time, and what that money could grow to if invested instead.
Every form of gambling is mathematically designed so that the operator always wins over time. The "house edge" — the percentage of every bet that goes to the casino, bookmaker, or lottery operator — is built into every game. This calculator makes that invisible tax visible. It does not show glamorous wins or lucky streaks. It shows the cold statistical outcome of regular gambling over months and years.
The calculator covers five gambling types: sports betting, slot machines, roulette, scratch cards, and lottery tickets. Each has a different house edge, and each is shown with the probability of a regular player being ahead after 1, 5 and 10 years of play. These probabilities are derived from published house-edge data and standard probability mathematics.
The house edge figures used in this calculator are based on published return-to-player (RTP) data from gambling regulators and academic literature. Sports betting carries a house edge of approximately 5–10% (bookmaker margin built into odds pricing). Slot machines typically operate at 94–96% RTP, giving a house edge of 4–6%. European roulette has a house edge of 2.7% (one zero on the wheel). Scratch cards typically return 65–70% of stakes, giving a house edge of 30–35%. The UK National Lottery returns approximately 50% of ticket revenue as prizes, giving a house edge of approximately 50%.
The win probability figures — the chance of being ahead after 1, 5 and 10 years of regular play — are derived from standard probability mathematics applied to the relevant house edge and assumed session frequency. These figures represent the probability of cumulative net winnings being positive after the stated period, assuming consistent betting behaviour. The probability decreases over time because the house edge compounds with every additional bet placed.
Problem gambling affects approximately 0.5% of the UK adult population, with a further 3.8% classified as "at-risk" gamblers (NHS Health Survey for England, 2018; Gambling Commission, 2023). The financial harm associated with problem gambling is well-documented: the average problem gambler in the UK loses approximately £1,200 per year to gambling (GamCare Annual Statistics, 2022–23). If you are concerned about your gambling, free support is available from GamCare at gamcare.org.uk or by calling 0808 8020 133.
The investment projection uses the S&P 500 historical average annual return of approximately 10%, compounded monthly (Shiller, R.J., Yale University). Past performance does not guarantee future results.
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