Enter the voltage (volts), the resistance (ohms), time (seconds), and the capacitance (Farads) into the calculator to determine the Capacitor Charge Current. 

Capacitor Charge Current Formula

The following formula is used to calculate the Capacitor Charge Current.

I = V / R * e ^{- (t/(RC))}
  • Where I is the Capacitor Charge Current (amps)
  • V is the voltage (volts) 
  • R is the resistance (ohms) 
  • C is the capacitance (Farads) 
  • t is the time (charge)

To calculate the capacitor charge current, divide the voltage by the resistance, then multiply by e to the power of the time over the resistance times capacitance.

How to Calculate Capacitor Charge Current?

The following example problems outline how to calculate Capacitor Charge Current.

Example Problem #1

  1. First, determine the voltage (volts). In this example, the voltage (volts) is determined to be 15 .
  2. Next, determine the resistance (ohms). For this problem, the resistance (ohms) is measured to be 10 .
  3. Next, determine the capacitance (Farads). In this case, the capacitance (Farads) is found to be 6.
  4. Next, determine the time. For this problem, the time is 5 seconds.
  5. Finally, calculate the Capacitor Charge Current using the formula above: 

I = V / R * e ^ 1 – (t/(RC))

Inserting the values from above and solving yields: 

I = 15 / 10 * e ^- (5/(10*6)) = 1.380 (amps)

Example Problem #2

Using the same method as above, determine the variables required by the formula. For this example problem, these are:

voltage (volts) = 20

resistance (ohms) = 15

capacitance (Farads) = 4

time (seconds) = 2

Enter these given values into the calculator or above yields: 

I = 20 / 15 * e ^ – (2/(15*4)) = 1.289 (amps)