Select the dealer's up-card and your hand above. The calculator shows how often the dealer busts, how often you bust if you hit, and which action basic strategy recommends.
Blackjack is the one casino game where your decisions change the house edge — from roughly 2% for a guesser to about 0.5% for someone playing perfect basic strategy. Every rule on the strategy chart comes from comparing two numbers: the dealer's chance of busting from the card you can see, and your chance of busting if you take another card. This calculator, one of our free player tools, gives you both and shows how they combine. The rules of the game are covered in how to play blackjack.
Dealer bust probability by up-card
The dealer has no choices: they hit until 17 or more (standing on soft 17 in the figures below, the S17 rule). Because the shoe is roughly 30% ten-value cards, the dealer's bust chance depends heavily on the up-card. The figures are for a multi-deck shoe and are the standard values used in strategy derivation.
| Dealer up-card | Bust probability | Reading |
|---|---|---|
| 2 | 35.3% | Weaker than it looks, but the dealer still makes a hand two times in three |
| 3 | 37.4% | Slightly weaker than a 2 |
| 4 | 40.3% | Bust card — the dealer's hand fails two times in five |
| 5 | 42.9% | Weakest up-card of all |
| 6 | 42.1% | Nearly as weak as 5; the classic 'stand and double' card |
| 7 | 26.0% | The cliff: bust chance drops by a third |
| 8 | 23.9% | Strong |
| 9 | 23.3% | Strong |
| 10, J, Q, K | 21.4% | Very strong; dealer makes 20 about a third of the time |
| Ace | 11.5% | Strongest (after checking for blackjack); dealer busts roughly one hand in nine |
Averaged over all up-cards the dealer busts about 28% of hands. If the dealer hits soft 17 (H17), the bust probabilities rise slightly for the ace and small cards, but the dealer also makes more 18s–21s, so H17 is worse for the player overall by about 0.2 percentage points of house edge.
Your bust probability if you hit a hard total
A hard total contains no ace counted as 11. Hit a hard 12 and you bust on any ten-value card; hit a hard 16 and anything above a 5 busts you. The figures below are the standard multi-deck approximations.
| Your hard total | Cards that bust you | Bust probability if you hit |
|---|---|---|
| 11 or less | None | 0% |
| 12 | 10, J, Q, K | 31% |
| 13 | 9 and above | 39% |
| 14 | 8 and above | 56% |
| 15 | 7 and above | 58% |
| 16 | 6 and above | 62% |
| 17 | 5 and above | 69% |
| 18 | 4 and above | 77% |
| 19 | 3 and above | 85% |
| 20 | 2 and above | 92% |
Soft totals (an ace counted as 11) cannot bust on a single hit, which is why basic strategy hits soft 17 and below against almost everything and doubles soft hands aggressively against a 5 or 6.
How the two numbers produce basic strategy
The intuition is simple: when the dealer is likely to bust, do not risk busting yourself; when the dealer is likely to make a hand, you must improve yours even at the risk of busting. The exact line is drawn by comparing the full expected value of each action, which the calculator does, but the bust numbers explain most of the chart.
| Your total | vs dealer 2–3 | vs dealer 4–6 | vs dealer 7–Ace | Why |
|---|---|---|---|---|
| 12 | Hit | Stand | Hit | 31% bust risk is low; against a 2 or 3 the dealer still makes a hand ~64% of the time, so you must improve |
| 13 | Stand | Stand | Hit | 39% bust risk now exceeds the benefit of improving against weak cards |
| 14 | Stand | Stand | Hit | Dealer 2–6 busts 35–43%; your 56% bust risk makes hitting worse than waiting |
| 15 | Stand | Stand | Hit (surrender vs 10 if offered) | Against 7+ the dealer makes a hand ~75% of the time; standing on 15 loses almost always |
| 16 | Stand | Stand | Hit (surrender vs 9, 10, A if offered) | Hitting 16 busts 62% of the time — but standing against a 10 wins only when the dealer busts, 21.4% |
Using the calculator with the strategy chart
Set the dealer's up-card
Read the dealer bust probability. Anything 7 or higher is a 'pat' card: assume the dealer will make 17+ and play to beat it.
Enter your hand
Hard or soft total, or a pair. The tool shows your bust probability on a hit and the recommended basic-strategy action.
Compare with the chart
Check the action against the full basic-strategy chart, which also covers doubles, splits and surrender. The calculator explains the why; the chart gives every answer.
Drill it
Numbers become habit only through repetition. The blackjack trainer on the practice page deals hands and marks each decision against basic strategy.
What the numbers do not cover
- Rule variations. Dealer hits soft 17, no doubling after splits, 6:5 blackjack payouts and continuous shuffling machines all shift the edge. A 6:5 payout alone adds about 1.4 percentage points — more than every strategy decision combined.
- Deck composition. The figures assume a full, random shoe. Card counters track the changing ratio of tens to small cards and adjust both bets and some decisions; see the blackjack strategy guide.
- Side bets. Perfect Pairs, 21+3 and insurance are not covered. Insurance is a bet that the dealer's hole card is a ten, at 2:1 — the true odds are about 2.25:1, giving a house edge of roughly 7% for a non-counter. Decline it.
- Variance. A 0.5% edge means an expected loss of £3 per hour at £10 a hand and 60 hands an hour, but the standard deviation per hand is about 1.15 units, so swings of ±£90 in an hour are normal.
Blackjack strategies
The full basic-strategy chart, rule-variation adjustments and an honest look at card counting.
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Open calculatorFrequently asked questions
What is the dealer's most likely bust card in blackjack?
A 5 up-card, which busts 42.9% of the time with the dealer standing on soft 17, closely followed by a 6 at 42.1% and a 4 at 40.3%. An ace is the least likely to bust at 11.5%, and a ten-value card busts 21.4%.
What are the odds of busting if I hit 16?
About 62% with a full multi-deck shoe: any 6 or higher breaks the hand. Basic strategy still hits 16 against a dealer 7 or higher (or surrenders against 9, 10 and ace where allowed), because standing wins only when the dealer busts, which happens 21–26% of the time.
Why does basic strategy say stand on 12 against a 4 but hit against a 2?
Because the dealer busts 40.3% of the time from a 4 but only 35.3% from a 2, and the expected value of hitting 12 — busting 31% of the time but improving otherwise — beats standing against a 2 and 3 while losing to it against 4, 5 and 6.
Does the dealer hitting soft 17 change these probabilities?
Slightly. Under H17 the dealer busts marginally more often from small cards and an ace, but also makes more strong hands, and the net effect is about 0.2 percentage points in the house's favour. Basic strategy changes in a handful of spots, such as doubling 11 against an ace.
How often does the dealer bust overall?
About 28% of hands across all up-cards with S17 rules, slightly more under H17. From 2 through 6 the rate is 35–43%; from 7 through ace it is 11–26%, which is why the chart treats 7 as the dividing line.
Is this calculator the same as a card-counting tool?
No. It assumes a full, random shoe and gives you the probabilities behind basic strategy. Card counting tracks the cards already dealt to estimate how the remaining shoe differs from that baseline; our blackjack strategy guide explains the Hi-Lo system and its real-world limits.