Enter the current and voltage moving in and out of a circuit into the calculator to determine the total power loss.

## Power Loss Formula

The following formula is used to calculate the power loss of an electrical circuit.

PL = Ii * Vi -  Io * Vo
• Where PL is the power loss (watts)
• Ii is the input current (amps)
• Vi is the input voltage (volts)
• Io is the output current (amps)
• Vo is the output voltage (volts)

To calculate power loss, subtract the product of the output current and voltage from the product of the input voltage and current.

## Power Loss Definition

A power loss is defined as the total difference between the input and output power of an electrical circuit due to resistances throughout the circuit. The power is calculated by multiplying the current by the voltage.

## How to calculate power loss?

First, determine the input current. For this example, the current at the input is measured to be 20 amps.

Next, determine the input voltage. For this problem, the input voltage is measured to be 20 volts.

Next, determine the output current. Measuring a point as close to the output as possible, the current is found to be 15 amps.

Next, determine the output voltage. Measuring at the same point as the step above, the output voltage reading is found to be 15 volts.

Finally, calculate the power loss using the formula:

PL = Ii * Vi – Io*Vo

= 20*20 – 15*15

= 175 Watts of power loss.