AC Wattage Calculator

Calculate AC power consumption for single-phase and three-phase electrical systems

Calculate AC Wattage

Select the type of AC current system

RMS voltage

RMS current through the load

Power factor ranges from 0 to 1 (default: 0.95 for efficient systems)

Power Calculation Results

0.00
Watts (W)
0.000
Kilowatts (kW)
0.000
Horsepower (HP)
0.0
BTU/hr
0.00 W
Active Power (P)
Real power consumed
0.00 VAR
Reactive Power (Q)
Power stored/returned
0.00 VA
Apparent Power (S)
Total power from source

Formula used: P = PF × I × V

Input values: V = 0.0 V, I = 0.000 A, PF = 0.95

Power factor angle: θ = 18.2°

Power Factor Analysis

✅ Excellent power factor (≥0.95). Very efficient electrical system.

Example Calculations

Single-Phase AC Motor

Voltage: 120 V (residential AC)

Current: 15 A

Power Factor: 0.8 (typical for motors)

Calculation: P = 0.8 × 15 × 120 = 1,440 W

Three-Phase Industrial Load

Line-to-line voltage: 480 V

Current: 25 A

Power Factor: 0.9

Calculation: P = √3 × 0.9 × 25 × 480 = 18,708 W

AC Power System Types

Single Phase

P = PF × I × V

Residential and small commercial

Three Phase L-L

P = √3 × PF × I × V

Industrial applications

3φN

Three Phase L-N

P = 3 × PF × I × V

Line-to-neutral systems

Power Factor Guide

Unity (PF = 1.0)

Perfect efficiency, resistive loads

Leading (PF > 0)

Capacitive loads, current leads voltage

Lagging (PF > 0)

Inductive loads, current lags voltage

Poor (PF < 0.7)

High reactive power, inefficient

Understanding AC Wattage and Power

What is AC Wattage?

AC wattage (or active power) is the actual power consumed by electrical devices in an alternating current circuit. Unlike DC power, AC power involves complex relationships between voltage, current, and phase angles due to reactive components.

Types of AC Power

  • Active Power (P): Real power consumed (Watts)
  • Reactive Power (Q): Power stored/returned (VAR)
  • Apparent Power (S): Total power from source (VA)

Power Factor Importance

Power factor (PF) represents the efficiency of power usage in AC circuits. It's the ratio of active power to apparent power, indicating how much of the supplied power is actually used for productive work.

Power Triangle Relationship

S² = P² + Q²

PF = P / S = cos(θ)

Q = S × sin(θ)

Applications: Motor sizing, electrical billing, power system design, energy efficiency analysis