3-Phase Power Calculator

3-Phase Power Calculator supports engineering calculations with transparent assumptions, practical result interpretation, and links to next-step technical resources.

Three-Phase Visualizer

Core Relationships

S = √3 × VLL × IL

P = S × PF

Q = ±√(S² − P²)

φ = arccos(PF)

VLL = √3 × VLN

Use positive Q for lagging (inductive) and negative Q for leading (capacitive) operation.

Balanced System Sketch

Power Triangle

Enter required values to render power triangle.

Real Power vs Power Factor

Enter required values to render PF sensitivity curve.

Inputs & Outputs

Voltage Reference

Reactive Nature

Voltage (required)

Line Current (required)

Real Power (calculated)

Power Factor (0-1)

Line-to-Line Voltage—

Line-to-Neutral Voltage—

Line Current—

Phase Angle—

Power Breakdown

Apparent Power (S)—

Real Power (P)—

Reactive Power (Q)—

Power Factor—

Three-Phase Fundamentals

In balanced systems, apparent power depends on line voltage and line current, while real power scales with power factor. Reactive power direction reflects lagging or leading behavior.

Magnitude Relationships

S = √3 × VLL × IL

P = S × PF

Q = ±√(S² − P²)

Voltage Reference Mapping

VLL = √3 × VLN

VLN = VLL / √3

Always align meter reference with equation input type.

Solver Reference Matrix

Choose the known-value set that matches your measurement context and solve remaining electrical quantities.

Known Set	Solved Outputs	Equation Path
VLL + IL + PF	S, P, Q, φ, VLN	S = √3 VLL IL; P = S × PF; Q = ±√(S² − P²)
P + VLL + PF	IL, S, Q, φ, VLN	IL = P / (√3 VLL PF)
P + IL + PF	VLL, S, Q, φ, VLN	VLL = P / (√3 IL PF)

Application Design Matrix

Map calculation output to field design decisions for feeders, correction stages, and plant-level audits.

Scenario	Objective	Recommendation	Critical Checks
Motor feeder sizing	Estimate current for breaker, cable, and thermal margin checks	Solve from rated power, line voltage, and realistic operating PF rather than nameplate PF alone.	Starting current, service factor, cable derating
Power factor correction planning	Reduce reactive burden and improve input current profile	Track Q sign and magnitude to compare lagging load demand against compensation target.	Overcompensation risk, capacitor step control, harmonics
Plant distribution audits	Map apparent vs real power utilization	Use consistent line-voltage reference and verify whether measured values are line or phase quantities.	Meter reference mismatch, unbalance effects, measurement class