Blackjack Strategy Calculator

How to Use This Calculator

1. Enter your hand total and select the dealer up card.
2. Choose Hard, Soft (has Ace), or Pair.
3. The calculator shows the basic strategy action and reason instantly.
4. Use dedicated tabs for hard totals, soft totals, and pair splitting.
5. Use Professional for Hi-Lo card counting true count and recommended bet sizing.

Formula

Example

Frequently Asked Questions

• What is basic strategy in blackjack? ▼
  Basic strategy is the mathematically optimal play for every hand vs every dealer up card, reducing the house edge to ~0.5%. It was computed by Baldwin et al. (1956) and refined by Edward Thorp in "Beat the Dealer."
• When should you always split in blackjack? ▼
  Always split Aces (two chances for a 10-card to make 21) and always split 8s (a hard 16 is the worst hand; splitting gives two better starting hands). Never split 10s (20 is too strong).
• What is the Hi-Lo counting system? ▼
  Assign +1 to cards 2–6, 0 to 7–9, and −1 to 10s and Aces. Running count ÷ decks remaining = true count. At true count +2 or higher, the player has an edge and should increase bets.
• Should you take insurance in blackjack? ▼
  Insurance is almost always a bad bet: it pays 2:1 but the chance a hole card is a 10 is only 30.8% (16/52) — far below the break-even 33.3%. Only take insurance at Hi-Lo true count ≥ 3.
• What is the house edge with perfect basic strategy? ▼
  With optimal basic strategy on a standard 6-deck game: ~0.5% house edge. Without strategy (guessing): ~2–3%. Card counting with a 1–12 spread can give the player a +0.5% to +1% edge.

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