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Transformer Calculator

Calculate turns ratio, voltage, current, impedance transformation, and efficiency

A transformer transfers AC power between two isolated circuits via a shared magnetic core. Turns ratio n = N1/N2 sets voltage and current scaling; an ideal transformer conserves power (V1 × I1 = V2 × I2).

Voltage, current, and impedance scaling

Voltage: V2 = V1/n. Current: I2 = I1×n. Impedance: Z_in = n² × Z_load — used for impedance matching to maximise power transfer.

Real-world losses

Copper losses (I²R in windings), core losses (hysteresis and eddy currents), and leakage flux all reduce efficiency. A well-designed 50/60 Hz transformer achieves 95–99% efficiency.