Estimate air conditioner running current from power, voltage, phase, and power factor, or solve Ohm's law for voltage, resistance, current, and power.

Air Conditioner Current Calculator

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AC Current
Ohm’s Law
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Air Conditioner Current Formula

The following formulas are used to estimate air conditioner running current from real power, voltage, and power factor (PF). 

I_{ac}=\frac{P_{ac}}{V_s\cdot PF}\quad \text{(single-phase)}
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I_{ac}=\frac{P_{ac}}{\sqrt{3}\,V_{LL}\cdot PF}\quad \text{(three-phase, balanced)}
  • Where Iac is the air conditioner running current (amps)
  • Pac is the air conditioner input (real) power consumption (watts) 
  • Vs is the RMS source voltage (volts) for single-phase (for three-phase, use line-to-line voltage VLL) 
  • PF is the power factor (unitless, 0 < PF ≤ 1)

To estimate an air conditioner’s running current, divide the real power by the voltage and power factor (and by √3 for a balanced three-phase load). Note: compressor starting (inrush) current can be several times higher than running current.

How to Calculate Air Conditioner Current?

The following two example problems outline how to calculate the Air Conditioner Current.

Example Problem #1:

  1. First, determine the air conditioner input power (watts). In this example, the air conditioner input power is measured to be 600 W.
  2. Next, determine the source voltage (volts). For this problem, the source voltage is 120 V.
  3. Then, determine the power factor (PF). In this example, PF = 0.90.
  4. Finally, calculate the Air Conditioner Current using the formula above. 

Iac= Pac / (Vs × PF)

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

Iac= 600 / (120 × 0.90) = 5.56 (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:

air conditioner input power (watts) = 2400

source voltage (volts) = 240

power factor (PF) = 0.85

Entering these values into the formula above gives : 

Iac= 2400 / (240 × 0.85) = 11.76 (amps)