How to Use the Blackjack Bust Probability Calculator
Deciding whether to hit or stand is the core decision in blackjack. This calculator computes the exact bust probability (going over 21) on your next card, based on a standard 52-card deck, using just your hand total and the dealer's up card.
Bust probability is the chance that the next card pushes your hand past 21, out of the 13 card ranks in the deck. For example, with a hand total of 16, any card of value 6 or higher (6,7,8,9,10,J,Q,K) causes a bust, so the probability is about 61.5%. A total of 11 or lower can never bust on the next card.
The basic strategy shown here is a simplified version of the mathematically verified casino basic strategy chart, assuming a multi-deck game where the dealer stands on soft 17. When the dealer's up card is weak (4-6), standing on lower totals tends to be favorable; when it's strong (7 or higher), hitting despite bust risk is usually better in the long run.
Frequently Asked Questions
Not necessarily. You should also weigh the dealer's up card. If the dealer shows a strong card, hitting can still be the better expected-value play even with some bust risk.
No. This calculator is based on hard hands. A soft hand, where the ace can flexibly count as 1 or 11, has a much lower bust risk and must be calculated separately.