Enter the apparent power (volt-amps, VA) and the line-to-line voltage (V) into the calculator to determine the 3‑phase line current (for a balanced 3‑phase system). 

3-Phase Current Calculator

VA → Current Current → VA

Calculate 3‑phase line current from apparent power (VA) and line‑to‑line voltage (V)


Related Calculators

3 Phase Current Formula

The following formula is used to calculate the 3‑phase line current from apparent power for a balanced 3‑phase system. 

I_L = VA/(\sqrt{3}\,V_{LL})
  • Where IL is the 3‑phase line current (amps)
  • VA is the apparent power (volt‑amps, VA) 
  • VLL is the line‑to‑line voltage (volts) 

To calculate the 3‑phase line current, divide the apparent power (VA) by the product of √3 and the line‑to‑line voltage. (For a wye system, VLL = √3 · VLN.)

How to Calculate 3 Phase Current?

The following two example problems outline how to calculate the 3‑phase line current from apparent power and line‑to‑line voltage.

Example Problem #1:

  1. First, determine the apparent power (VA). In this example, the apparent power is measured to be 45 VA.
  2. Next, determine the line‑to‑line voltage (VLL). For this problem, the line‑to‑line voltage is measured to be 5 V.
  3. Finally, calculate the 3‑phase line current using the formula above: 

IL = VA / (√3 · VLL)

Inserting the values from above and solving the equation with the input values gives: 

IL = 45 / (√3 · 5) ≈ 5.1962 (amps)


Example Problem #2: 

Using the same process as example problem 1, we first define the variables outlined by the formula. In this case, the values are:

apparent power (VA) = 75

line‑to‑line voltage (VLL) = 6

Entering these values into the formula above gives : 

IL = 75 / (√3 · 6) ≈ 7.2169 (amps)