Transformer Copper Loss Calculator

Copper loss is the power wasted as heat in a transformer's wire windings — knowing it is critical for sizing transformers and evaluating efficiency. Enter your primary winding current and resistance, plus your secondary winding current and resistance, into the Transformer Copper Loss Calculator to find the Total Copper Loss in watts. You'll also see the individual Primary Winding Loss and Secondary Winding Loss broken out separately.

A
Ω
A
Ω

Results

Total Copper Loss

--

Primary Winding Loss

--

Secondary Winding Loss

--

More Electrical & Electronics Tools

Frequently Asked Questions

What is copper loss in a transformer?

Copper loss, also known as I²R loss, is the heat produced by electrical current flowing through the resistance of transformer windings. It varies with the square of the current and increases with load.

How is transformer copper loss calculated?

Copper loss is calculated using the formula: Loss = I²R, where I is the winding current and R is the winding resistance. Total loss is the sum of primary and secondary winding losses.

What factors affect copper losses in transformers?

Copper losses are affected by winding current, resistance of conductors, temperature, and load conditions. Higher currents and resistance result in greater losses.

How can transformer copper losses be minimized?

Copper losses can be reduced by using larger conductor cross-sections to lower resistance, optimizing winding design, using high-conductivity materials, and operating at appropriate load levels.

What is the difference between core losses and copper losses?

Core losses occur in the transformer core due to hysteresis and eddy currents, remaining constant regardless of load. Copper losses occur in windings and vary with the square of the load current.

Why do copper losses increase with temperature?

Copper resistance increases with temperature, following the temperature coefficient of resistance. As transformers heat up during operation, winding resistance increases, leading to higher copper losses.

How do copper losses affect transformer efficiency?

Copper losses reduce transformer efficiency by converting electrical energy to heat. Higher copper losses mean more energy waste and lower overall efficiency, especially at higher loads.