True count vs. running count: how to convert

Updated October 31, 2026

The problem with the running count alone

A running count of +6 means that, so far, six more low cards than high cards have been played. Since a full shoe is perfectly balanced, that tells you the cards still in the shoe contain six more high cards (tens and aces) than low cards. Whether that matters depends on how many cards those six extra high cards are mixed into.

• Situation A: five decks left (260 cards). Six extra high cards spread across 260 cards is a tiny tilt, only about one extra high card per deck. The shoe is almost perfectly average.
• Situation B: one deck left (52 cards). The same six extra high cards are now packed into just 52 cards, which is six extra high cards per deck. The shoe is noticeably rich in tens and aces.

Both situations have a running count of +6, but Situation B is far more favorable to you. The fix is to convert the running count into a true count, which measures the count per deck remaining.

The formula

True count = running count ÷ decks remaining

The true count is much more stable than the running count: it describes the actual composition of the remaining cards.

Estimating decks remaining

You don’t need to be exact. Casino tables have a discard tray where used cards pile up. With practice you’ll learn to eyeball the height of the discard stack, and compare it with the size of a single deck, which is about 52 cards, roughly an inch thick. Many counters round to the nearest half deck.

If you know the shoe size and the number of cards dealt, you can compute it: decks remaining = (total cards − cards seen) ÷ 52. For example, in a six-deck shoe (312 cards), after 130 cards have been seen there are 182 cards left, which is 3.5 decks. The practice table’s HUD shows this estimate, rounded to the nearest half deck, so you can compare it with your own.

Worked examples

1. Half the shoe gone. Six decks, 156 cards dealt, running count +9. Decks remaining = (312 − 156) ÷ 52 = 3. True count = 9 ÷ 3 = +3.
2. Late in the shoe. Six decks, 260 cards dealt, running count +4. Decks remaining = 52 ÷ 52 = 1. True count = +4.
3. Negative count. Eight decks, 208 cards dealt (4 decks gone, 4 left), running count −8. True count = −8 ÷ 4 = −2. A negative true count means the shoe is rich in low cards: bad for you, good for the dealer.
4. Fractions. Running count +7 with 2.5 decks left gives +2.8. Most players round or truncate toward zero and call it “+2” or “+3”.

Why rounding is fine

The goal isn’t perfection. The edge differences between a true count of +2.8 and +3 are tiny, and the cost of making mistakes in a casino from trying to be too precise is larger. Pick one consistent rounding rule and stick to it.

Systems that skip the division

Some systems are unbalanced: their tags don’t sum to zero over a full deck. The most popular is KO (Knock-Out), whose tags add up to +4 per deck. You compensate by starting the count at a number that depends on how many decks are used (the “initial running count”: 0 for a single deck, −20 for six decks), and you act when the running count crosses a fixed “key” number. This avoids division entirely, at the cost of a little precision.

Common true-count mistakes

• Dividing by decks dealt instead of decks remaining. If four decks have been dealt from a six-deck shoe, you divide by the two decks that are left, not the four that are gone.
• Letting the estimate drift. Re-check the discard tray every few hands rather than carrying an old estimate through the whole shoe.
• Forgetting that late in the shoe the count swings more. With half a deck left, a running count of +3 is a true count of +6. Small running counts become large true counts, so the same arithmetic matters most at the end of the shoe.
• Overthinking the decimals. A consistent, slightly rough estimate beats a precise one you can’t keep up at game speed.