This copper loss calculator finds the resistive (I²R) power loss in a winding, the main load loss in transformers and motors. Enter the current and winding resistance above.
Formula
Copper loss P = I² × R
Example
I = 10 A, R = 0.5 Ω: P = 10² × 0.5 = 50 W.
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Frequently Asked Questions
How do I calculate copper loss?
Square the winding current and multiply by the winding resistance: P = I squared times R.
Why is it called copper loss?
It is the heat lost in the copper windings due to their resistance, also called I-squared-R loss.
How do I reduce copper loss?
Use a larger conductor to lower resistance, or reduce the current for the same power by raising voltage.