The charging time calculated above is only valid if sufficient current (A) flows during charging. Since the charging current is highest at the beginning of the process, it's sufficient to calculate that value for checking.
IStart = V / R
To calculate the charging time of a capacitor, you first need the time constant tau (τ):
τ = R × C
After one time constant (τ), the capacitor reaches 63% of the charging voltage.
after 2τ 86%
after 3τ 95%
after 4τ 98%
after 5τ 99%...
Theoretically, the capacitor never reaches 100% charge, but in practice, it's considered fully charged after 5τ.