Enter the current through resistor 1 (amps), the current through resistor 2 (amps), and the current through resistor 3 (amps) into the calculator to determine the Branch Current. 

Branch Current Formula

The following formula is used to calculate the Branch Current.

Ib = Ir1 + Ir2 + I r3

  • Where Ib is the Branch Current (amps)
  • Ir1 is the current through resistor 1 (amps) 
  • Ir2 is the current through resistor 2 (amps) 
  • Ir3 is the current through resistor 3 (amps) 

How to Calculate Branch Current?

The following example problems outline how to calculate Branch Current.

Example Problem #1

  1. First, determine the current through resistor 1 (amps). In this example, the current through resistor 1 (amps) is determined to be 4 .
  2. Next, determine the current through resistor 2 (amps). For this problem, the current through resistor 2 (amps) is measured to be 5 .
  3. Next, determine the current through resistor 3 (amps). In this case, the current through resistor 3 (amps) is found to be 9.
  4. Finally, calculate the Branch Current using the formula above: 

Ib = Ir1 + Ir2 + I r3

Inserting the values from above and solving yields: 

Ib = 4 + 5 + 9 = 18 (amps)


Example Problem #2

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

current through resistor 1 (amps) = 90

current through resistor 2 (amps) = 10

current through resistor 3 (amps) = 10

Enter these given values into the calculator or above yields: 

Ib = 90 + 10 + 10 = 110 (amps)