Enter the wattage rating and the source voltage into the calculator to determine the amperage draw of the appliance. This calculate can also determine the wattage rating and source voltage.

Amps Draw Formula

The following formula is used to calculate an amperage draw amount.

A = WR / SV
  • Where A is the amps draw (amps)
  • WR is the wattage rating (watts)
  • SV is the source voltage

To calculate amps draw, divide the wattage ratting by the source voltage.

Amps Draw Definition

What are amps draw? An amperage draw is a total current in amps delivered to an appliance or device that is dependent on the source voltage and wattage rating of the device.

Example Problem

How to calculate amps draw?

  1. First, determine the wattage rating.

    For this example, we are looking at a lightbulb with a wattage rating of 200 watts.

  2. Next, determine the source voltage.

    The light bulb is connected to a standard outlet, so the source voltage is 120 volts.

  3. Finally, calculate the amps draw.

    Using the formula, the total current is 200/120 = 1.66 amps.


Are amps drawn or pushed? Amps are always drawn from a source as opposed to being pushed.

What determines amps draw? The number of amps or current that a device or appliance requires is dependent on the source voltage and the maximum power of the device, known as the wattage rating.