Z = U₀ / I
Z = P / (I² * cosφ)
Z = (U₀² * cosφ) / P
Z = S / I²
Z = U₀² / S
Z = Q / (I² * sinφ)
Z = (U₀² * sinφ) / Q
Z = R / cosφ
Z = U / I
Z = P / (I² * cosφ)
Z = (U² * cosφ) / P
Z = S / I²
Z = U² / S
Z = Q / (I² * sinφ)
Z = (U² * sinφ) / Q
Z = R / cosφ
Z = U / I
Z = P / (√3 * I² * cosφ)
Z = (√3 * U² * cosφ) / P
Z = S / (√3 * I²)
Z = (√3 * U²) / S
Z = Q / (√3 * I² * sinφ)
Z = (√3 * U² * sinφ) / Q
Z = R / cosφ
Z = Impedance (Ω)
R = Resistance (Ω)
P = Active power (W)
S = Apparent power (VA)
Q = Reactive power (VAr)
I = Current (A)
U₀ = Voltage [L - N] (V)
U = Voltage [L - L] (V)
cosφ = Power factor
Impedance is the total opposition of a circuit to the flow of alternating electric current, measured in ohms (Ω). It includes resistance, inductive reactance, and capacitive reactance, and is a key parameter in AC circuit analysis.
Select the type of current:
Direct Current (DC): Constant flow from positive to negative pole
Alternating Current (AC): Reverses direction and amplitude periodically at constant frequency
System configurations:
Single-phase: Two conductors (phase + neutral)
Two-phase: Two phase conductors; neutral may be distributed
Three-phase: Three phase conductors; four-wire system includes neutral
Note: Impedance is only meaningful in AC circuits; in DC, impedance equals resistance.
Electric potential difference between two points.
For single-phase: Enter Phase-Neutral voltage
For two-phase or three-phase: Enter Phase-Phase voltage
Flow of electric charge through a material, measured in amperes (A).
The power actually consumed by a load and converted into useful energy (e.g., heat, motion).
Unit: Watts (W)
Formula:
P = V × I × cosφ
Power that alternately flows in inductors or capacitors without being transformed into other forms of energy.
Unit: Volt-Ampere Reactive (VAR)
Formula:
Q = V × I × sinφ
The product of RMS voltage and current, representing total power supplied by the source.
Unit: Volt-Ampere (VA)
Formula:
S = V × I
Ratio of active power to apparent power, indicating efficiency of power usage.
Formula:
PF = P / S = cosφ
where φ is the phase angle between voltage and current. Value ranges from 0 to 1.
Opposition to current flow due to material properties, length, and cross-sectional area.
Unit: Ohm (Ω)
Formula:
R = ρ × l / A
Impedance ( Z ) is defined as:
Z = V / I
For a series RLC circuit:
Z = √(R² + (XL - XC)²)
Where:
R: Resistance
XL = 2πfL: Inductive reactance
XC = 1/(2πfC): Capacitive reactance
f: Frequency (Hz)
L: Inductance (H)
C: Capacitance (F)
If XL > XC, the circuit is inductive; if XC > XL, i t is capacitive.
1. Impedance affects short-circuit current, voltage drop, and protection device selection in power systems
2. Low power factor increases line losses; consider reactive power compensation
3. Use this tool to back-calculate unknown impedance values from measured voltage and current
Compare inductive reactance XL and capacitive reactance XC. The circuit is inductive if XL＞XC, capacitive if XC＞XL. Series resonance occurs when XL=XC and impedance equals pure resistance.
This calculator returns impedance magnitude and does not label inductive or capacitive nature directly.
Input phase‑neutral voltage for single‑phase mode; input line‑to‑line voltage for two‑phase and three‑phase modes. Wrong voltage type yields wrong impedance values. Voltage and current must be RMS values measured under identical operating conditions for Z=V/I.
Impedance magnitude represents only the numerical size for rough estimation of current and voltage drop.
Complex impedance contains both real resistive part and imaginary reactive part to derive phase angle, ideal for detailed analysis of power factor, resonance and phase relationship. This tool outputs impedance magnitude only.
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