Blackjack Card Counting Calculator
The Hi-Lo system
| Cards | Value |
|---|---|
| 2, 3, 4, 5, 6 | +1 |
| 7, 8, 9 | 0 |
| 10, J, Q, K, A | −1 |
You can read the chart in a minute. Getting it into your hands takes longer, and that is what the drill is for Fast Values.
True Count — the running count divided by the number of physical decks remaining (8 minus those dealt). We use physical decks rather than playable ones, because the cards behind the cut card are never dealt yet still shape the probabilities: the shoe was shuffled across all 8 decks.
Cut card / penetration — the dealer shuffles at 50% of the shoe, meaning after 208 cards. Cards behind the cut card are never played. When the cut card appears, press Reset.
Positive count — more high cards remain in the shoe (tens, face cards, aces). That favors you: better odds of a blackjack and of strong hands.
Negative count — more low cards remain in the shoe. That favors the dealer, so cut your bets and play conservatively.
Bet sizing (conservative 1:6)
| True Count | Bet |
|---|---|
| ≤ −2 | 1 unit (better not to play) |
| −1 to +1 | 1 unit |
| +2 | 2 units |
| +3 | 3 units |
| +4 | 4 units |
| +5 and up | 5–6 units (max) |
Why a conservative 1:6 spread? A 1:6 spread gives a small but steady edge and draws less attention. Wider spreads (1:8, 1:12, 1:16) earn more, and the house spots you far sooner and may show you the door. For eight decks at 50% penetration, 1:6 is a sound compromise between safety and return.
Watch out: this approach is backed by sources such as Blackjack Apprenticeship, bj21.com, and Stanford Wong on cover play. Stay discreet anyway: do not jump your bets in steps, and do not look like a professional.
Calculator FAQ
How do I use the calculator at a live table?
Tap the button matching each card as it comes out: 2–6 is +1, 7–9 is 0, 10 through ace is −1. The calculator keeps the running count, converts it to a true count using the decks remaining, and shows your bet size. The arrow keys are faster: ↑ is +1, ↓ is −1, ← is 0, and backspace takes back the last card.
What are the running count and the true count?
Running count is the plain sum of the values of every card you have seen. True count is the running count divided by the number of decks still in the shoe, and only that number tells you how to bet. Without the conversion the running count is misleading: +6 early in an eight-deck shoe means almost nothing, while +6 with one deck left is a lot. There is a full explanation in how card counting works.
Is using this calculator legal?
Counting in your head is a legal mental skill, not cheating. A casino may still refuse to deal to anyone, and using a device is a crime in Nevada. This site is an educational tool and runs no games of chance. More in is card counting legal.
Does the calculator work for online blackjack?
At a live dealer table yes, because the cards come from a real shoe. Against U software running a random number generator no. There the cards are restored after every hand and there is nothing for a count to track. The same goes for tables with a continuous shuffler. The differences are covered in does card counting work online.
Why do I have to set the deck count and penetration?
Because both feed the calculation. The deck count is what the running count gets divided by, and penetration tells you when the dealer will shuffle. Most American shoe games run six or eight decks with the cut card past the middle. Set both with the button Table rules, which also recomputes the house edge.
What does “your edge” in percent mean?
It is the gap between what the game returns at the current true count and the house edge for the rules you set. A negative number means the game is still in the casino’s favor. A positive one means you are ahead, which with eight decks happens from around a true count of +1.
Does the calculator store my data?
Nothing is sent anywhere. Your browser keeps only your settings (theme, table rules, keyboard shortcuts) and the owls you have collected in the trainer. No account and no sign-up.
Counting Trainer
