1. What is Power Calculation?

Power calculation determines the rate of energy transfer in an electrical circuit. It's measured in watts (W) and represents how much work can be done by the electrical current.

2. How Does the Calculator Work?

The calculator uses the power formula:

Where:

• \( P \) — Power in watts (W)
• \( V \) — Voltage in volts (V)
• \( I \) — Current in amperes (A)
• \( PF \) — Power factor (unitless, between 0 and 1)

Explanation: The formula calculates real power in AC circuits. For DC circuits or when power factor is 1, it simplifies to P = V × I.

3. Importance of Power Calculation

Details: Accurate power calculation is essential for circuit design, energy efficiency analysis, electrical safety, and proper equipment sizing.

4. Using the Calculator

Tips: Enter voltage in volts, current in amperes, and power factor (1 for DC circuits or resistive AC loads). All values must be valid (voltage > 0, current > 0, 0 ≤ PF ≤ 1).

5. Frequently Asked Questions (FAQ)

Q1: What is power factor?
A: Power factor is the ratio of real power to apparent power, representing how effectively current is being converted into useful work.

Q2: When should I use power factor = 1?
A: For DC circuits or purely resistive AC loads (like incandescent lights or heaters), use PF = 1.

Q3: What are typical power factor values?
A: Motors: 0.8-0.9, fluorescent lights: 0.7-0.9, computers: 0.6-0.7. Perfect efficiency is 1.

Q4: How does this relate to energy bills?
A: Utilities often charge for apparent power (kVA), so low power factor means higher costs for the same real power.

Q5: Can I calculate power for three-phase systems?
A: This calculator is for single-phase. Three-phase requires multiplying by √3 (1.732).