Enter the transformer output power (watts) and the total power losses (watts) into the calculator to determine the Transformer Efficiency.

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## Transformer Efficiency Formula

The following formula is used to calculate the Transformer Efficiency.

**Et = Po / (Po + PL) *100**

- Where Et is the Transformer Efficiency (%)
- Po is the transformer output power (watts)
- PL is the total power losses (watts)

## How to Calculate Transformer Efficiency?

The following two example problems outline how to calculate the Transformer Efficiency.

**Example Problem #1:**

- First, determine the transformer output power (watts). In this example, the transformer output power (watts) is given as 50.
- Next, determine the total power losses (watts). For this problem, the total power losses (watts) is given as 5.
- Finally, calculate the Transformer Efficiency using the equation above:

Et = Po / (Po + PL) *100

Inserting the values from above and solving the equation:

Et = 50 / (50 + 5) *100 = 90.909 (%)

**Example Problem #2: **

Using the same process as above, first define the variables required by the formula. In this case, these values are:

transformer output power (watts) = 60

total power losses (watts) = 7

Entering these values yields:

Et = 60 / (60 + 7) *100 = 89.55 (%)