Calculate true count, player advantage, and optimal bet sizing
Enter your current count and deck status
Practice with different count situations
Key concepts at a glance
Card counting works by tracking the ratio of high to low cards remaining. High cards (10-A) favor the player, low cards (2-6) favor the dealer. In Hi-Lo, add +1 for 2-6, 0 for 7-9, -1 for 10-A. A positive true count indicates player advantage. At +2 true count, the player has roughly a 1% edge. Bet more when the count is positive, less when negative.
Essential knowledge for counters
Common questions about card counting
Card counting tracks the ratio of high cards (10, J, Q, K, A) to low cards (2-6) remaining in the deck. When more high cards remain, players have an advantage because: blackjacks are more likely, doubling down is more profitable, and the dealer busts more often. Counters bet more when the deck is "hot" (rich in high cards).
Running count is the raw cumulative count from the start of the shoe. True count normalizes this for the number of decks remaining. With 6 decks and a running count of +12 after 3 decks dealt, true count = +12 / 3 = +4. True count better represents actual advantage and is used for betting decisions.
Card counting is not illegal - it is using your brain to play better. However, casinos are private property and can refuse service to anyone. They may "back off" counters (ask them to leave blackjack) or ban them entirely. Using devices to count is illegal.
Start with Hi-Lo. It is the most popular, well-documented, and offers a good balance of power and simplicity. More complex systems like Wong Halves or Zen add marginal accuracy but are much harder to use under casino conditions. Master Hi-Lo before considering others.
Skilled counters with adequate bankroll can expect 0.5-1.5% edge over the house. At $25 average bet, 100 hands/hour, this is $12.50-$37.50/hour expected profit. However, variance is extreme - you can easily lose $5,000 in a session even with an edge. Most counters need $20,000+ bankroll.