Convert running count to true count instantly. Estimate decks remaining from the discard tray. Get bet ramp recommendations. Built for Hi-Lo, KO, Hi-Opt II, and any divisor-based card counting system.
Enter your running count and decks remaining. Reverse mode gives you the running count threshold needed to hit a target true count.
Don't know decks remaining off the top of your head? Enter total decks in the shoe and an estimate from the discard tray.
The simple practice ramp recommended by Blackjack Apprenticeship for Hi-Lo and KO. Bet 1 unit at neutral or negative counts (table minimum), then add 1 unit per true count up to your maximum spread. Edge values are approximate for typical 6-deck S17 rules.
| True count | Bet | Edge | What's happening |
|---|---|---|---|
| ≤ 0 | 1u | −0.5% | House edge. Bet table minimum and ride it out. |
| +1 | 2u | ~0% | Edge is roughly even. Slight bet increase signals you're paying attention. |
| +2 | 3u | +0.5% | First true edge. Most index plays start kicking in here. |
| +3 | 4u | +1.0% | Solid edge. Insurance becomes profitable at TC +3. |
| +4 | 5u | +1.5% | Strong edge. Most counters cap their main spread here for low cover. |
| +5 | 6u | +2.0% | Very strong. Scaling further depends on bankroll and casino heat tolerance. |
| +6+ | 7u+ | +2.5%+ | Rare. Consider table max if your bankroll supports it. Wonging in around this point is common. |
The running count tells you how the deck has shifted from neutral. The true count tells you how much that shift matters right now, given how much deck is left to play. A running count of +5 with 5 decks remaining is barely above neutral. A running count of +5 with 1 deck remaining is a goldmine. The number's identical; the situation isn't.
That's it. The whole conversion. Standard practice is to round the result down (floor) to be conservative — a true count of +2.5 floors to +2, and you act as if you're at +2. This matches how the Illustrious 18 index numbers and most published deviation tables are calibrated.
This is the part that takes practice. Most counters glance at the discard tray between hands and estimate to the nearest half-deck. Colin Jones at Blackjack Apprenticeship ran simulations comparing precision levels:
The takeaway: half-deck precision captures almost all the gain. Quarter-deck is theoretical max, but the cost is more obvious staring at the discard tray, which raises heat. Most pros stick to half-deck.
Counting works because of how much shoe gets dealt before the dealer shuffles. A casino can have great rules (S17, DAS, surrender, 3:2 blackjack) but if they cut off 2.5 decks of a 6-deck shoe (~58% penetration), the count rarely gets high enough late enough to extract meaningful EV. Conversely, a so-so ruleset with 80%+ penetration is highly beatable.
If your true count is rising late in a deep-penetration shoe, that's where the money is made. Most of the EV from card counting comes from a small percentage of hands with a high true count near the end of well-penetrated shoes.
The 1-unit-per-true-count ramp on this page comes from Blackjack Apprenticeship's published practice ramp. It's not the optimal ramp — bigger spreads make more money on paper. But it's the simplest ramp that captures most of the EV, and it's what nearly every counter learns first. As you advance, you'll customize ramps based on bankroll, risk tolerance, and how much heat you can absorb.
The edge percentages in the ramp table are approximations for typical 6-deck S17 DAS rules. Other rule sets shift them slightly. CVCX is the standard tool for custom ramp simulation, and Blackjack Apprenticeship's Blackjack Calculator gives EV-by-spread data for typical rule sets.
Once you can convert true count smoothly, the next layer is index play — deviating from basic strategy when the count crosses certain thresholds. Don Schlesinger's Illustrious 18 + Fab 4 covers the 22 highest-impact deviations and is now live as a dedicated reference. Pair it with the 9 counting systems comparison and the basic strategy chart for the complete card counter's toolkit.
The questions counters ask about converting and using the true count.
The true count is the running count divided by the number of decks remaining in the shoe. It tells you the count per deck, which is the actual number you use to make betting and playing decisions. A running count of +6 with 3 decks remaining is a true count of +2 — and that +2 is what you act on, not the +6.
Look at the discard tray. With practice you can eyeball how many decks of cards are stacked there, and subtract from the total decks in the shoe. Most counters round to the nearest half-deck.
Colin Jones at Blackjack Apprenticeship has shown that half-deck precision captures roughly 95% of the EV available from quarter-deck precision, with much less mental load and less suspicious staring at the tray.
If you use a balanced system (Hi-Lo, Hi-Opt II, Omega II, Zen, Wong Halves, Uston APC) — yes. Balanced systems require the conversion because the running count's meaning changes as the shoe depletes.
If you use an unbalanced system (KO, Red 7), you skip the conversion and bet directly off the running count once you hit the system's pivot point.
Standard practice is to floor (round down) the true count. A running count of +5 with 2 decks remaining gives 2.5, which floors to true count +2. The reasoning is conservative betting and play — you want to be confident the true count is at least that high before deviating from basic strategy.
The QFIT and Blackjack Apprenticeship simulators both default to flooring; their published index numbers (Illustrious 18, etc.) assume floored true counts.
The simple practice ramp recommended by Blackjack Apprenticeship: bet 1 unit at true count 0 or below (table minimum), then add 1 unit per true count up to your maximum spread. So at TC +1, bet 2 units. At TC +2, bet 3 units. At TC +3, bet 4 units.
This ramp captures most of the edge available from card counting and is simple enough to execute under casino pressure. More aggressive ramps exist; they make more money on paper but are easier for casinos to spot.
Penetration is the fraction of the shoe that gets dealt before the dealer shuffles. If a casino cuts off 2 decks of a 6-deck shoe (33% cut, 67% penetration), card counting works but with reduced edge. If they cut off 2.5 decks (~58% penetration), counting becomes barely profitable. Below that, it's a losing game.
The calculator flags configurations where the math doesn't pencil out, so you don't waste time counting at unbeatable tables.
Yes — the running count to true count conversion (running count divided by decks remaining) is identical for every balanced counting system. Hi-Lo, Hi-Opt I, Hi-Opt II, Omega II, Zen, and Wong Halves all use the same conversion.
The bet ramp on this page is calibrated for level-1 systems like Hi-Lo and KO; level-2 and level-3 systems can use the same ramp shape, but the true counts you'll see may differ in magnitude.
Per published simulations from Blackjack Apprenticeship: full-deck precision gives a baseline EV. Half-deck precision adds about 6% more EV. Quarter-deck precision adds another 1% on top of that.
Almost all of the value comes from getting half-deck precision right; the gain from quarter-deck precision is small and comes at the cost of more obvious staring at the discard tray. Half-deck is the practical sweet spot.