how to calculate output power of transformer?

To calculate the output power of a transformer, you can use the formula: ( P_{out} = V_{out} times I_{out} ), where ( P_{out} ) is the output power in watts, ( V_{out} ) is the output voltage in volts, and ( I_{out} ) is the output current in amperes. Ensure that the transformer is operating under its rated conditions for accurate results. Additionally, consider efficiency losses if a more precise calculation is needed.