Blackjack Odds Calculator

What Is Basic Strategy?

Basic strategy is the set of mathematically optimal decisions for every blackjack hand, calculated by computer simulation of millions of hands. It doesn't guarantee a win on any given hand, but over time it minimizes the house edge to around 0.5% at most tables, with no card counting required.

How to Use This Calculator

Tap the two (or more) cards in your hand, then tap the dealer's upcard. The calculator instantly shows whether to Hit, Stand, Double, or Split, using the same logic as the full chart below.

Why the Rules Matter

This chart assumes the most common rule set: 4-8 decks, dealer stands on soft 17, double after split allowed, no surrender offered. If your table hits soft 17, allows surrender, or uses a single deck, a few cells shift, so always check the rules card at your table.

Common Mistakes

The biggest basic-strategy leaks: standing on hard 16 against a dealer 7 or higher (you should hit), not splitting 8s against a dealer 10 (you should always split), and not doubling 11 against everything but an Ace.

Check the Felt Before You Check the Chart

House rules move the house edge more than any playing decision you will make in an hour, and they are printed on the table before you sit down.

The one that matters most is the blackjack payout. A table paying 6 to 5 instead of 3 to 2 costs roughly 1.4 percent, which is nearly three times the entire edge basic strategy is fighting. A 6 to 5 table played perfectly is worse than a 3 to 2 table played carelessly. If the felt says 6 to 5, find another table.

After that, look for whether the dealer stands or hits on soft 17, whether doubling after a split is allowed, and whether surrender is offered. This calculator assumes four to eight decks, dealer stands on soft 17, doubling after split allowed, and no surrender, which is the most common combination in US casinos.

Weak Dealer, Strong Dealer

Most of the chart follows from one distinction. The dealer has no choices: they must draw until reaching 17, then stop. That rigidity splits their upcards into two groups.

Upcards 2 through 6 are weak. The dealer must draw and busts somewhere in the range of 35 to 42 percent of the time, rising as the card rises toward 5 and 6. Against these you play passively: stand on stiff hands and let the dealer break.

Upcards 7 through Ace are strong. The dealer busts far less, closer to one time in four or fewer, and frequently finishes in the high teens. Against these, surviving is not enough. You hit totals that would be reckless against a weak dealer, because standing on them loses more often than busting does.

The gap between a dealer 6 and a dealer 7 is the largest single jump in the game, and it is why the same hand of 14 stands against one and hits against the other.

A Soft Hand Cannot Bust on the Next Card

An Ace counts as one or eleven, whichever helps, so a hand containing a usable Ace has no bad next card, only worse totals.

That single fact drives the whole soft section. Soft 17 never stands against anything: it either doubles or hits. Soft 18 is the hardest hand on the chart because it does all three things, doubling against 3 through 6, standing against 2, 7, and 8, and hitting against 9, 10, and Ace. That last one is the most commonly misplayed hand in casual blackjack.

The moment a card pushes the Ace down to one, the hand is hard and plays by hard rules. Ace-6-9 is a hard 16, not a soft anything.

What Perfect Play Is Actually Worth

Under the rules above, playing every hand correctly leaves the house with an edge of roughly half a percent. That is half a percent of everything you wager, not of your buy-in, which is a much larger number over a session.

The useful comparison is against not using it. Typical casual play, standing on stiff hands, missing doubles, splitting tens, taking insurance, runs somewhere around 2 percent or more. Basic strategy does not make you a winner. It cuts the cost of playing by roughly three quarters.

Anyone selling you a system that beats the house edge through betting patterns is selling you something that does not work. No sequence of bet sizes changes the expected value of the underlying hands.

Decline Insurance, Every Time

Insurance is a side bet on whether the dealer's hole card is worth ten. It pays 2 to 1, so it needs to hit more than a third of the time to break even. With the Ace showing, roughly 31 percent of the remaining cards are ten-value.

That shortfall gives the house an edge of about 5.9 percent on the insurance money, more than ten times the edge on the main game. Even money, offered when you hold a blackjack against an Ace, is the identical bet under a friendlier name.

Declining costs no memorization and no arithmetic at the table. It just means ignoring the prompt, and it saves more per hour than most of the playing decisions people agonize over.

Play With Money You Can Afford to Lose

This calculator gives you the mathematically correct play for a hand. It cannot make blackjack a winning proposition, and nothing on this site is a prediction of results or a suggestion that you should gamble.

Decide before you sit down what you are willing to lose, and stop when you reach it rather than when the cards tell you to. Do not raise your bets to chase a loss, and do not treat a winning streak as evidence of anything.

If gambling has stopped being entertainment, the National Problem Gambling Helpline is 1-800-522-4700, or ncpgambling.org.