Enter the wattage and the voltage of the transformer into the calculator to determine the transformer amperage.

## Transformer Amperage Formula

The following formula is used to calculate transformer amperage.

I = P / V

- Where I is the amperage (current) (amps)
- P is the power (wattage) (watts)
- V is the voltage (volts)

## Transformer Amperage Definition

A transformer amperage is defined as the total current a transformer will draw given the power and voltage of the transformer system.

## How to calculate transformer amperage?

**Example Problem #1: **

First, determine the wattage, also known as the power, that the transformer uses. For this example, the wattage is found to be 500 watts.

Next, determine the voltage of the transformer. For this example, we will use a standard voltage of 120 volts.

Finally, calculate the amperage/current of the transformer using the formula above:

I = P/V

= 500/120

= 4.166 amps.

**Example Problem #2: **

In this next example, we will use a wattage of 1000 watts and a voltage of 60 volts.

Using the formula we find the amperage to be:

I = P/V

= 1000/60

= 16.667 amps.