The blackjack house edge calculator tells you what a table costs before you sit down. Set the decks, what blackjack pays, the dealer’s soft 17 rule and the doubling and splitting rules, and it shows the edge, your expected value per hand and the average loss per hour. Free to use, with the numbers worked out from the rules on the table card.
Blackjack house edge calculator: what each rule is worth
A good shoe game, with 6 decks, 3:2 blackjack, the dealer standing on soft 17 and doubling allowed after a split, has a house edge of about 0.42% if you play perfect basic strategy. Every rule nudges that up or down. Some barely matter. One matters more than all the others together.
| Rule | Change in house edge |
|---|---|
| Blackjack pays 6:5 instead of 3:2 | +1.39% |
| Blackjack pays 1:1 | +2.27% |
| Dealer hits soft 17 | +0.22% |
| Double on 10 or 11 only | +0.18% |
| No doubling after a split | +0.14% |
| No hole card (dealer’s second card comes later) | +0.11% |
| 8 decks instead of 6 | +0.03% |
| Late surrender | −0.08% |
| Resplit aces | −0.08% |
| 2 decks instead of 6 | −0.22% |
| 1 deck instead of 6 | −0.48% |
Look at the top line. A 6:5 payout on blackjack turns a 0.42% game into roughly 1.8%. You’ll get a blackjack about once every 21 hands, and each time you’re paid £12 on a £10 bet instead of £15. That’s the whole difference, and it’s why a 6:5 sign is the first thing to check.
Expected value per hand and per hour
Expected value is the house edge turned into money. Bet £10 a hand at 0.42% and you lose 4.2p a hand on average. That sounds like nothing. Now play 70 hands an hour for three hours: you’ve put £2,100 through the game and the average loss is £8.82.
Same bet, same three hours, at a 6:5 table where the dealer hits soft 17: the edge is about 2.03% and the average loss is £42.63. Nearly five times as much for a payout change most people don’t notice.
These are averages. Blackjack swings a lot over a few hours, so you’ll often finish well ahead or well behind. Over months of play the average is where you end up.
Your play counts too
The rules figure assumes perfect basic strategy. Most players don’t manage that. Standing on 12 against a 2, or never splitting 8s against a 10, quietly adds to the edge. A few slips like that cost around half a percent. Playing by feel usually costs somewhere between 1.5% and 2.5%, which is more than the worst rule on the table. The blackjack strategy chart fixes most of it, and the blackjack trainer drills it until you stop checking.
If you’re deciding a single hand rather than a whole table, the blackjack calculator shows the odds of hitting or standing. Side bets are a separate game with a much bigger edge: see the side bets calculator.
How accurate is it?
The calculator adds up published rule effects, one at a time, from the base game. That’s how most rule tables are built, and it’s within a few hundredths of a percent of a full simulation for normal games. Odd combinations, like a single deck with 6:5 and early surrender, can drift a little further. A continuous shuffling machine doesn’t change the edge per hand, but it does deal more hands per hour, so put that in the hands field.
The payout on a blackjack is the single biggest rule: see the blackjack payout calculator for 3:2 against 6:5, or run your rules in the blackjack simulator.
Insurance has its own, much higher edge: see the blackjack insurance calculator. To compare blackjack with other games, see best odds in casino.