1. What is the Power Formula?

The power formula P = V × I × PF calculates electrical power in watts, where V is voltage in volts, I is current in amps, and PF is the power factor (a dimensionless number between 0 and 1).

2. How Does the Calculator Work?

The calculator uses the power formula:

Where:

• \( P \) — Power in watts
• \( V \) — Voltage in volts
• \( I \) — Current in amps
• \( PF \) — Power factor (0 to 1)

Explanation: This formula calculates the real power in an AC circuit, accounting for the phase difference between voltage and current through the power factor.

3. Importance of Power Calculation

Details: Accurate power calculation is essential for electrical system design, energy consumption analysis, circuit protection sizing, and equipment selection.

4. Using the Calculator

Tips: Enter voltage in volts, current in amps, and power factor (0 to 1). All values must be valid (voltage > 0, current > 0, 0 ≤ PF ≤ 1).

5. Frequently Asked Questions (FAQ)

Q1: What is power factor and why is it important?
A: Power factor represents the ratio of real power to apparent power. A low power factor indicates inefficient power usage and may result in higher electricity costs.

Q2: When should I use power factor = 1?
A: Use PF = 1 for DC circuits or purely resistive AC loads where voltage and current are in phase.

Q3: What are typical power factor values?
A: Residential: 0.95-1.0, Industrial: 0.7-0.9, Motors at full load: 0.8-0.9, Fluorescent lights: 0.5-0.9.

Q4: How does power factor affect electrical systems?
A: Low power factor increases current flow for the same power output, leading to larger conductor sizes, higher losses, and reduced system capacity.

Q5: Can this calculator be used for three-phase systems?
A: This calculator is for single-phase AC systems. For three-phase systems, use P = √3 × V × I × PF.