What is the percentage of charge on a capacitor at the 4 time constant?

At 4 time constants, a capacitor in an RC charging circuit is approximately 98.2% charged. The charging equation shows that after each time constant (τ), the charge on the capacitor increases significantly, approaching its maximum value asymptotically. By the fourth time constant, the capacitor is effectively considered fully charged, with negligible difference in charge compared to the maximum value.