Blackjack Odds Explained: House Edge, RTP and Your Chances of Winning

Blackjack odds are some of the best in the casino, but only if you play well and pick the right table. With basic strategy and good rules, the house edge is around 0.5%, which means an RTP of about 99.5%. In a typical game you will win roughly 42% of hands, push about 8.5% and lose about 49%.

You lose more hands than you win, yet the house edge stays small. That’s because blackjacks pay 3:2, and doubling and splitting let you put more money on the table when the odds favour you. Bad rules or sloppy decisions can quickly multiply the edge.

This guide covers the core probabilities, dealer bust rates, how each table rule shifts the odds, worked examples in pounds, and the mistakes that cost players the most.

These figures assume a standard multi-deck game played with perfect basic strategy. Exact decimals vary slightly with the rules and number of decks, so treat them as close guides rather than fixed values.

The single-deck blackjack figure is easy to check. You need an ace (4 of 52 cards) and a ten-value card (16 of the remaining 51), in either order: 2 × (4/52) × (16/51) = 128/2,652 ≈ 4.83%. With more decks, a card you have already been dealt removes less from the shoe, so the chance drops a little.

If you lose about 49% of hands and win about 42%, how is the house edge only about half a percent? Not every hand pays the same amount.

• Blackjacks pay 3:2. A £10 natural returns £15 profit, not £10. You get one roughly every 21 hands.
• Doubling down lets you put twice the stake on hands where you are the favourite, such as 11 against a dealer 6.
• Splitting turns weak hands, such as a pair of 8s, into two better starting hands. It can also double your money on strong spots like a pair of aces.
• Surrender, where offered, lets you get back half your stake on hopeless hands.

The casino’s main advantage is that you act first. If you bust, you lose straight away, even if the dealer later busts too. Those extra payouts and options win back most, but not all, of that advantage. Our guide to doubling down and splitting pairs shows exactly when to use them.

The dealer’s visible card is the most important information on the table. The figures below are for a six-deck game where the dealer stands on soft 17 and peeks for blackjack. Independent calculations agree on these numbers to within about a percentage point.

This explains much of basic strategy. Against a 4, 5 or 6, the dealer busts more than four times in ten, so you often stand on a stiff hand like 13 and let the dealer take the risk. Against a 7 or higher, the dealer usually makes a hand, so you need to improve weak totals yourself. When the dealer hits soft 17, bust rates rise slightly for most upcards, but the dealer also makes more strong hands. Overall, that rule works in the casino’s favour.

Players often ask how risky it is to take a card on a stiff hand. The table uses an infinite-deck approximation, which is close enough for shoe games. The four ten-value ranks make up 16 of every 52 cards.

A 62% chance of busting on 16 sounds like a reason never to hit. But against a dealer 10, standing on 16 only wins if the dealer busts, which happens less than a quarter of the time. Basic strategy weighs both risks. That’s why it tells you to hit 16 against a 10 (or surrender if allowed) but stand on 16 against a 6.

Two blackjack tables can look the same and still have very different odds. Here is roughly how common rules shift the house edge, measured against a standard eight-deck game:

The 6:5 payout is by far the costliest rule. It adds more to the house edge than every other common rule put together. Fewer decks help players, but single-deck games often make up for it with 6:5 payouts. That trade-off is nearly always a bad deal.

House edge is the average share of every pound wagered that the casino expects to keep over the long run. Results over a single session can swing widely either way.

Example 1: a good table

Picture six decks, a 3:2 payout, the dealer standing on soft 17, and doubling after splitting allowed. Played with basic strategy, the house edge is about 0.4%. At £10 a hand for 100 hands, you wager £1,000 in total. Your expected loss is about £1,000 × 0.4% = £4.

Example 2: the same table with worse rules

Now make the dealer hit soft 17 (about +0.2%) and cut the blackjack payout to 6:5 (+1.39%). The edge rises to around 2%. The same 100 hands at £10 now cost about £20 on average, roughly five times as much.

Example 3: the insurance bet

Insurance pays 2:1 if the dealer’s ace turns out to be a blackjack. To break even, the dealer would need a ten-value hole card one time in three (33.3%). The real chance is about 4 in 13, or 30.8%. On a £5 insurance bet, the expected value is 2 × £5 × 0.308 − £5 × 0.692 ≈ −£0.38, a house edge of roughly 7.7%. Unless you are counting cards and know the shoe is rich in tens, turn it down. This includes the ‘even money’ offer when you hold a blackjack.

RTP is simply 100% minus the house edge, so a 0.5% edge equals a 99.5% RTP. Online blackjack providers usually publish an RTP in the game’s help or info screen. That figure assumes optimal play, so your real return will be lower if you deviate from basic strategy. For example, Evolution’s Infinite Blackjack, a popular live dealer game, is listed with an RTP of roughly 99.5% for optimal play.

Before you sit down at any table, check three things in the rules panel: the blackjack payout, whether the dealer hits or stands on soft 17, and the number of decks. Side bets such as Perfect Pairs or 21+3 carry much higher house edges than the main game, so look up their RTP separately. Treat them as entertainment, not part of your strategy.

RNG blackjack shuffles before every hand, and most live tables use continuous shufflers or shallow cut cards. Card counting is therefore ineffective in most online games. Your odds come down to the rules and your decisions. Our guide to choosing an online blackjack table covers what to look for.

• Playing 6:5 tables. This one rule adds 1.39% to the house edge. Look for 3:2.
• Taking insurance or even money. As shown above, this is a bet with a house edge of roughly 7–8%.
• Never hitting a stiff hand. Standing on 12–16 against a dealer 7 or higher gives away value on every hand.
• Not doubling or splitting when you should. Most of your edge-recovering profit comes from these moves. Skipping them out of caution costs money.
• Believing a win or loss is ‘due’. In shuffled or RNG games, past hands do not change the next one, and betting systems do not change the house edge.
• Ignoring bonus terms. Many casinos count blackjack at a reduced rate towards wagering requirements, or exclude it entirely. Check the contribution table first. Our casino bonus terms guide explains how.

If you are new to the game, start with how to play blackjack and basic strategy before thinking about the finer points of the odds.

• With good rules and basic strategy, blackjack’s house edge is about 0.5% (RTP around 99.5%), one of the lowest in the casino.
• You will still lose more hands than you win, roughly 49% against 42%. The 3:2 payout, doubling and splitting make up most of the difference.
• Rules matter: always choose 3:2 over 6:5, prefer tables where the dealer stands on soft 17, and use surrender where it is offered.
• Skip insurance and treat side bets as expensive extras.
• For other table games, compare with our roulette odds and payouts guide.

Even the best blackjack odds still favour the casino. Over time, you should expect to lose money, not make it. Set a budget and a time limit before you play, never chase losses, and stop if gambling stops being fun. Gambling is for adults aged 18 and over only. If it is causing you problems, use the deposit limits and self-exclusion tools at your casino and get support from a gambling help service in your country.