Blackjack Calculator
Bust odds and rule impact
Blackjack is the one casino game where your decisions genuinely move the house edge. Perfect basic strategy takes a typical table down to roughly 0.5%, while the table rules on payouts, doubling and dealer soft 17 shift it by a few tenths of a percent each.
Use this calculator to see the bust probability of hitting any hard total, the odds of being dealt a natural, and how each rule your table uses adds to or subtracts from the house edge.
Used for the bust probability below.
House edge
0.500%
With perfect basic strategy
Bust chance on 16
61.54%
1 in 1.6
Dealt a natural
4.75%
1 in 21.1
Expected loss over 100 hands
5.00
Long-run average, not a session result
Edge figures use the published rule-variation table against a 6-deck, S17, DAS, 3:2 baseline and assume perfect basic strategy. Deviating from basic strategy typically costs another 1-2%.
How to read the results
- Bust chance assumes a full shoe: any hard total of 12 or higher risks busting on a hit.
- A 6:5 blackjack payout is the single most expensive rule at most tables — it adds about 1.4% to the house edge.
- Fewer decks favour the player; dealer hitting soft 17 favours the house.
- The result assumes correct basic strategy; playing by feel costs considerably more.
Frequently asked questions
What is the house edge in blackjack?
About 0.5% with basic strategy at a decent table. A 6:5 payout, dealer hitting soft 17 and no doubling after split can push it above 2%.
What are the odds of busting when I hit?
0% on 11 or less, roughly 31% on 12, and rising by about 8 percentage points per point after that, up to 92% on hard 20.
Should I ever take insurance?
No, unless you are counting cards. Insurance pays 2:1 but wins only about 31% of the time, giving it a house edge above 7%.
Related calculators
These tools are informational. They describe the mathematics of casino games; they do not predict outcomes and no calculator can overcome a house edge. Gambling involves real financial risk — 18+ only, and seek help if it stops being entertainment.