Casino House Edge Calculator

Free Casino House Edge Calculator: quick casino house edge calculator for everyday decisions. No signup needed.

A gambling odds calculator converts raw probability into expected value (EV) — the average financial outcome per bet or ticket if you played the same game an infinite number of times. Understanding EV is the single most important concept in rational gambling: every casino game and lottery has a negative EV for the player, meaning the house always wins on average. The calculator covers lottery odds (combinatorial probability), casino house edge (expected loss per session), poker and sports bet EV (using pot odds and decimal odds), and raffle win probability. Discount Calculator is a useful companion tool for understanding how small probabilities accumulate over many plays.

The UK Gambling Commission estimates that approximately 0.5% of the population are problem gamblers, and a further 3.8% are at moderate risk. The odds and EV figures this calculator produces are informational — their consistent message is that gambling is entertainment with a cost, not an investment strategy. The house edge on most games means long-run profit for players is statistically impossible.

Select the relevant tab: Lottery, Casino, Poker/Sports Bet, or Raffle.
For Lottery: enter the pool size (total numbers to choose from), the picks per ticket, your ticket cost, and the jackpot value. The calculator returns the exact odds and expected value per ticket.
For Casino: select a game preset (Roulette, Blackjack, Slots, Baccarat) or enter a custom house edge percentage. Enter your bet per round and session length to see expected loss.
For Poker EV: enter pot size, call amount, and your estimated win probability. For Sports Bet EV: enter the decimal odds and your probability estimate for the outcome.
For Raffle: enter total tickets sold, tickets you hold, and prize value to see your exact win probability and EV.

Odds and expected value formulas

Lottery odds = C(pool, picks) = pool! ÷ (picks! × (pool − picks)!). For the UK National Lottery (6 from 59): C(59,6) = 45,057,474 — roughly 1 in 45 million.

Expected Value (EV) = (Win probability × Net gain) − (Loss probability × Stake). A positive EV bet favours the player; negative EV favours the house.

Casino expected loss = Bet per round × Rounds per hour × House edge %. Example: £10 bet, 50 rounds/hour, 2.7% roulette house edge = £13.50 expected loss per hour.

Poker pot odds EV = (Pot size × Win%) − (Call amount × (1 − Win%)). A positive result means calling is mathematically correct.

Sports bet EV = (Decimal odds × Win probability) − 1. A result above 0 indicates value; below 0 means the bookmaker has priced in an unfavourable margin.

Understanding your odds results

House edges by game type

Common house edges: European Roulette 2.70%, American Roulette 5.26%, Baccarat (banker bet) 1.06%, Blackjack (basic strategy) 0.5–1.0%, Slot machines 2–15% (varies by machine and jurisdiction), UK National Lottery approximately 50% (only 50p per £1 goes to prizes). The lower the house edge, the slower you lose on average — but you still lose long-run.

Lottery EV is almost always deeply negative: a £2 National Lottery ticket with 1-in-45-million jackpot odds and a £5M jackpot has an EV of approximately −£1.89, meaning you lose 94.5p per £1 played on average. Raffle EV can occasionally be positive for small local raffles with few tickets sold and large prizes relative to ticket cost.

Everyday Life tips and best practices

Set a fixed entertainment budget for gambling before you start — decide on a sum you are comfortable losing entirely and stop when it is gone, regardless of whether you are up or down.
Blackjack with basic strategy has the lowest house edge of any casino table game (~0.5%). Card counting is legal but almost impossible to do profitably in modern casinos with frequent deck shuffles and multi-deck shoes.
Sports betting edges are embedded in the bookmaker's odds margin — most bookmakers build in a 5–10% margin (overround) across a market, meaning the total implied probability across all outcomes exceeds 100%.
Lottery syndicates increase your number of tickets (and win probability) proportionally but reduce individual payout by the same proportion — they do not improve your EV.
Near-misses on slot machines are a deliberate design feature — they trigger the same psychological reward response as a win but return nothing. Recognising this can help you assess slot play more objectively.
Use the GamStop self-exclusion scheme (UK) if gambling is affecting your finances, relationships, or mental health. It is free and covers all UK Gambling Commission-licensed operators.

UK National Lottery jackpot odds: 1 in 45,057,474. EuroMillions jackpot: 1 in 139,838,160. [Camelot / The Lotter]
UK Gambling Commission estimates the gross gambling yield (GGY) of licensed operators at approximately £14.1 billion in 2022–23.
Prevalence of problem gambling in UK adults: approximately 0.5% (around 300,000 people). [UKGC Gambling Participation Survey, 2023]
Average UK household spend on National Lottery tickets: approximately £3.40/week. [Camelot annual report]

Common mistakes to avoid

The Gambler's Fallacy — believing past results influence future independent events. A roulette wheel has no memory; after 10 consecutive reds, the probability of black on the next spin remains exactly 48.6%.
Confusing probability with certainty — a 1-in-14-million lottery win probability does not mean you will win in 14 million plays. You could win on play 1 or never win in 100 million plays.
Ignoring the house edge when calculating "expected winnings" — the correct figure is expected loss, not expected win, for nearly all commercial gambling.
Treating poker skill edge as equivalent to positive EV in the long run — even skilled players face variance; a positive EV strategy can produce losing sessions over thousands of hands.

Gambling in the UK is regulated by the UK Gambling Commission under the Gambling Act 2005. All commercial gambling operators serving UK customers must hold a Gambling Commission licence. The legal age for most forms of gambling in the UK is 18. If you are concerned about your gambling, contact the National Gambling Helpline on 0808 8020 133 (free, 24/7) or visit GamCare.org.uk. This calculator is for informational and educational purposes only; it does not encourage gambling and the results should not be used as the basis for gambling decisions.