Formula
True count equals running count divided by estimated decks remaining. A running count of +8 with four decks left is TC +2; the same +8 with one deck left is TC +8.
Why estimation matters
Bad deck estimation creates bad bets. If you overstate the true count, you overbet weak shoes. If you understate it, you miss profitable spots.
Practical rounding
Most players floor or truncate the true count for conservative betting decisions. The important point is consistency across the ramp and deviation chart.