AC Power Calculator

Power Factor, instantly.

Enter your circuit parameters and get power factor, apparent power, reactive power, and phase angle — with a live power-triangle diagram and the formulas behind every result.

Power Factor — Single-phase (1φ)0.606
Apparent Power3.30 kVA (volt-amperes)
Reactive Power2.62 kVAR
Phase Angle52.7°degrees
P (W)QS (VA)φPower triangle
Apparent Power
S = V × I (1φ) | S = √3 × V × I (3φ)
Total volt-amperes drawn from the supply.
Power Factor
PF = P / S
Ratio of real power to apparent power. 1.0 is ideal.
Reactive Power
Q = √(S² − P²)
Energy stored and returned each cycle by inductors / capacitors.
Phase Angle
φ = arccos(PF)
Angle between voltage and current phasors, in degrees.

Guides

25 guides
Guides

Protect Your Appliances from Electrical Hazards: What Actually Matters

How voltage fluctuations, overloads, and poor wiring damage appliances. Practical steps to protect equipment at home and reduce the risk of electrical faults.

Jun 18, 2026
Guides

Measuring Power Factor with a Clamp Meter: A Practical Guide

Learn how to measure power factor with a clamp meter, including single and three-phase methods, a worked example, and safety guidance.

Jun 15, 2026
Guides

Power Factor for Welding Machines and Other Reactive Loads

How welding machines affect power factor, why transformer welders have low swinging PF, and how to size circuits and correction for reactive loads.

Jun 14, 2026
Guides

Detuned Reactors and Capacitor Bank Protection

Learn how detuned reactors protect capacitor banks from harmonic resonance, with tuning factor selection, worked examples, and other protection methods.

Jun 13, 2026
Guides

Power Factor in Data Centers: Why It Drives Energy Cost

How power factor shapes UPS sizing, rack capacity, and energy bills in data centers — with a worked kW vs kVA example.

Jun 12, 2026
Guides

Overcorrection and Leading PF: The Risks of Too Many Capacitors

Fixed capacitor banks can push power factor leading at light load, raising voltage and triggering utility penalties. Here's what to watch for.

Jun 11, 2026
Guides

How I Meaningfully Cut My Electricity Bill (What Worked, What Didn't)

A credible account of real electricity savings: which changes moved the needle on a monthly bill, which were overhyped, and what the numbers actually looked like.

Jun 10, 2026
Guides

Power Factor vs. Efficiency: Two Different Things People Confuse

Power factor and efficiency sound similar but measure completely different things. Learn the real distinction and why it matters for your electricity bill.

Jun 10, 2026
Guides

How to Calculate Power Factor from Watts and Volt-Amperes

Learn how to calculate power factor from watts and VA using PF = W / VA, with worked examples for single-phase and three-phase systems.

Jun 9, 2026
Guides

Harmonics and Power Factor: Why VFDs Complicate Correction

VFDs distort current waveforms and create harmonics that make standard capacitor banks dangerous. Learn why and how to mitigate it.

Jun 8, 2026
Guides

Automatic Power Factor Correction (APFC) Panels: How They Work

Learn how APFC panels use a PF relay and switched capacitor stages to maintain target power factor automatically in industrial facilities.

Jun 7, 2026
Guides

Cosine Phi Explained: Phase Angle and Power Factor

Understand cosine phi, phase angle φ, and how PF = cos φ connects the power triangle to real electrical calculations.

Jun 6, 2026
Guides

Power Factor for Solar PV Inverters: What Installers Should Know

How solar PV inverters handle power factor, grid-code reactive power requirements, volt-VAR modes, and a worked example at 0.95 leading PF.

Jun 5, 2026
Guides

Synchronous Condensers vs. Capacitor Banks for PF Correction

Compare synchronous condensers and capacitor banks for reactive power compensation: cost, response speed, harmonic behavior, and which fits your application.

Jun 4, 2026
Guides

How to Save Electricity Responsibly: Choices That Actually Add Up

A practical look at saving electricity at home and work: which changes have real impact, what renewable options cost today, and how to track your actual consumption.

Jun 3, 2026
Guides

Why Induction Motors Have Low Power Factor at Partial Load

Learn why induction motors have poor power factor at light loads, how magnetizing current is the culprit, and what you can do about it.

Jun 3, 2026
Guides

Power Factor in Three-Phase Systems: Calculations and Examples

Learn how to calculate power factor in three-phase systems, with formulas for balanced and unbalanced loads, line vs phase quantities, and a worked example.

Jun 2, 2026
Guides

How to Read a Power Factor Meter

Learn how to read analog and digital power factor meters, understand lag vs lead readings, and decide when correction is needed.

Jun 1, 2026
Guides

Displacement vs. True Power Factor: Harmonics and THD

Displacement power factor measures the fundamental frequency phase angle. True power factor also accounts for harmonic distortion. Learn how THD links them.

May 30, 2026
Guides

kVA vs. kW vs. kVAR: Understanding the Power Triangle Units

Learn the difference between kVA, kW, and kVAR, how they relate through the power triangle, and what each unit actually sizes in AC electrical systems.

May 28, 2026
Guides

How to Improve Power Factor: Capacitors, Motor Loading, and Utility Penalties

Practical guide to power factor correction: when to add capacitors, how to size them, why partially loaded motors hurt PF, and how utilities charge for low power factor.

May 27, 2026
Guides

Power Factor Penalty Charges: How Utilities Bill for Low PF

Learn how utilities calculate power factor penalty charges, kVA billing, and demand surcharges, with a worked example and bill comparison table.

May 26, 2026
Guides

Leading vs. Lagging Power Factor: What Causes Each and Why It Matters

Learn what causes leading and lagging power factor, how inductive and capacitive loads affect phase angle, and why the difference matters for real systems.

May 24, 2026
Guides

Sizing Power Factor Correction Capacitors: How to Calculate kVAR

Learn how to size power factor correction capacitors using the kVAR formula Qc = P·(tan φ1 − tan φ2), with worked examples and a multiplier table.

May 22, 2026
Guides

What Is Power Factor? Real Power, Reactive Power, and the Power Triangle

Power factor measures how efficiently your electrical system converts apparent power into useful work. Learn real vs reactive power, the power triangle, and why PF matters.

May 20, 2026