Enter the resistance in ohms and capacitance in farads into the calculator to determine the total time to charge a capacitor.

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## Capacitor Charge Time Formula

The following formula can be used to calculate the charge time of a capacitor.

T = R * C * 5

- Where T is the time (seconds)
- R is the resistance (ohms)
- C is the capacitance (farads)

## Capacitor Charge Time Definition

A capacitor charge time is defined as the time it takes a capacitor to charge to 99%. This value is equal to 5 capacitor time constants.

## Capacitor Charge Time Example

How to calculate capacitor charge time?

**First, determine the resistance.**Measure the resistance of the capacitor.

**Next, determine the capacitance.**Calculate the capacitance of the capacitor.

**Finally, calculate the charge time.**Calculate the capacitor charge time using the equation above.

## FAQ

**How long does a capacitor take to charge?**

A capacitor will reach a 99% charge after 5 time constants and 63.2% after just one time constant. The time constant is calculated using the formula t = R*C. Typically either 4 or 5 time constants a capacitor is considered full charge. (It will never reach 100% charge.

**How long does a capacitor take to discharge?**

Conversely a capacitor will discharge only 36.8% after one time constant, but also reach near 99% discharge at around 5 time constants.