Blackjack House Edge: A Calculator for Every Rule, Payout and Variant

House edge is an average, written as a percentage of the bet you place before the cards are dealt. If a rule set has a house edge of 0.62%, then over a huge number of rounds the casino keeps that share of the money you start each round with. It describes the game, and it says nothing about the next hand, the next hour or the next visit.

It is not a prediction. A session of a few hundred hands is dominated by luck: the result can be far above or far below the average, and the distance between a typical session and the average is many times larger than the average itself. The edge only becomes visible when hands are counted in the many thousands.

It is also not a measure of how often you win. A hand can be won nearly as often as it is lost and the house still comes out ahead, because blackjack pays more than an even win, doubles and splits put more money on the table when the player is favoured, and the player must act before the dealer. A player who hits and stands by the published strategy loses the least the rules allow. Every figure here assumes that strategy. A player who ignores it pays extra, and no rule change in this table can undo that.

The figures on this page are per starting bet. One round of blackjack starts with one bet and can end with several: a double puts a second bet on the same hand, and each split creates another hand with its own bet. The average result of a whole round, in units of the first bet, is the figure shown. Doubles and splits are counted in the result, not in the bet it is divided by.

A second reading divides the same average loss by everything actually put at risk in the round, including doubled and split money. That number is smaller, because the divisor is larger. Some variants publish it, and it is labelled as such where it appears. The two are never mixed: a per-starting-bet figure is only ever compared with another per-starting-bet figure.

To turn the percentage into money, multiply it by the total of the starting bets over the hands played. The calculator does this for 100 hands at a bet you choose and labels the result as an average. An hour of play is a different number again, because it depends on how many rounds are dealt per hour, which varies with how full the table is and how fast the dealer works. The percentage never changes with the speed of the game, but the cost per hour does.

Every change below is measured against the comparison rules, at 0.62%, with one rule changed and the others left alone. The figures come from the same table as the calculator. The right-hand column of the calculator shows the same idea for any combination, with the steps applied in turn.

Number of decks. More decks help the house. A single deck gives 0.05%, which is 0.57 percentage points below the comparison rules. Two decks give 0.39%, four give 0.56% and eight give 0.65%. The reason is card removal: in a small shoe, each card you are dealt changes the make-up of the cards left more, and that favours the player.

Dealer on soft 17. A dealer who stands on soft 17 instead of hitting it cuts the house edge by 0.21 percentage points, to 0.41%. A soft 17 is a hand of ace and six counted as 17 or 7. Hitting it lets the dealer improve a hand that would otherwise sit at 17.

Doubling. Restricting doubles takes away a player's best moves. Doubling only on hard 9 to 11 raises the edge by 0.11 points, to 0.72%. Doubling only on hard 10 and 11 raises it by 0.20 points, to 0.82%.

Double after split. Losing the right to double on a hand that came from a split adds 0.14 points, for an edge of 0.76%. It is a small rule that comes up on every pair of eights, nines and sevens against a weak dealer card.

Resplitting aces. Most tables let you split aces once and then deal one card to each. Allowing a resplit of aces lowers the edge by 0.07 points, to 0.55%. The gain is small because a fresh ace after a split ace is rare.

Surrender. Late surrender lets you give up half your bet after the dealer has checked for blackjack. It lowers the edge by 0.09 points, to 0.53%, but only when it is used on the few hands where a half bet is worth more than playing on.

Split limit. The number of hands you may split to matters least. Stopping at three hands moves the edge to 0.63%, and allowing no resplit at all moves it to 0.67%.

The payout for a natural is the largest single change a table can make. Paying 6 to 5 means a bet of 10 returns 12 instead of 15. On the comparison rules, 6 to 5 raises the edge by 1.36 percentage points, to 1.98%. Paying only 1 to 1, even money, raises it by 2.27 points, to 2.88%.

No other rule takes as much per round, because the shortfall is paid on every natural, round after round. A 6 to 5 payout cancels the benefit of every favourable rule in the table at once: no amount of surrender, resplitting or favourable doubling gets the player back to a table that pays 3 to 2.

The calculator covers a flat payout on every natural.

Rules interact, because each one changes which hands the others apply to. That is why the calculator reads the result for your exact combination instead of adding up single changes, and why the ladder applies rules in turn: the steps always add up to the final figure, but which rule gets credit for an overlap depends on the order.

Three combinations show the spread. Single deck, blackjack paying 6 to 5, dealer hitting soft 17 and double after split gives 1.44%. Six decks with the dealer standing on soft 17 gives 0.41%. Eight decks, dealer standing on soft 17 and late surrender gives 0.36%. The most player-friendly rule set in the whole table comes out at -0.19%, where a minus sign means the player is ahead on average, and the least friendly at 3.27%.

That is a spread of several percentage points from rules alone, before any skill is involved. Reading the rule card before sitting down is worth more than any playing trick.

Variants change the rules more than a table does, so the house edge by variant is the quickest way to see what each game costs. The list below ranks the games on this site by the headline house edge of their own rules, using the same playing method. Spanish 21 removes the ten-spot cards from the shoe and pays bonuses to make up for it. Free Bet Blackjack gives free doubles and splits but pushes the player's hand when the dealer reaches 22. European blackjack has no hole card, so a dealer natural can cost a player a doubled or split bet. Pontoon is the related British and Australian game, dealt with its own rules.

A lower number is better for the player, but two games with the same figure can feel very different at the table, because one may reach it through frequent small wins and the other through rare large ones. Where a game has no figure, the list says why instead of inventing one.

Start from the rule card of the table you are looking at, set each rule in the blackjack house edge calculator, and read the result. If a rule is missing from the card, treat it as the less favourable option. Then look at the ladder: it shows which rule costs you the most, which tells you where a table is really charging you.

This blackjack house edge calculator gives you the house edge by rule, one control at a time, and the ranking above gives the house edge by variant. Compare two tables by changing one control at a time and watching the figure move. Set the bet to see the average cost per 100 hands, then remember it is an average over very many hands and not a forecast for tonight.