Physical-to-Per-Unit Impedance Calculator

Base Quantities

Base Apparent Power (S_base)

MVA

Base Voltage (V_base, line-to-line)

System Frequency (f)

Physical Parameters (enter at least one)

Resistance (R)

Inductance (L)

Capacitance (C)

Formulas Used

Z_base = V_base² / S_base

Y_base = 1 / Z_base

R_pu = R / Z_base

X = 2πfL → X_pu = X / Z_base

B = 2πfC → B_pu = B / Y_base

S_base in VA, V_base line-to-line in V, frequency in Hz. Capacitance is treated as shunt susceptance.

About This Calculator

This calculator converts physical electrical parameters into per-unit values for use in RMS and EMT studies. Enter the base apparent power, base voltage, and system frequency along with any combination of resistance, inductance, or capacitance.

Inductance is converted to series reactance, and capacitance is treated as shunt susceptance. Intermediate values (X in ohms, B in siemens) are shown for transparency.

For background on these conversions, see: Per-Unit Impedance from Physical Parameters.

For base quantity derivations, see: Per-Unit System: Base Quantities and Their Relationships.