1. What is the Watts Formula?

The watts formula calculates real power in an electrical circuit using voltage, current, and power factor. It's fundamental for determining actual power consumption in AC circuits.

2. How Does the Calculator Work?

The calculator uses the power formula:

Where:

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

Explanation: The formula accounts for both the magnitude of voltage and current, as well as their phase relationship through the power factor.

3. Importance of Power Factor

Details: Power factor represents the ratio of real power to apparent power. A PF of 1 means all power is real (resistive loads), while lower PF indicates reactive components (inductive or capacitive loads).

4. Using the Calculator

Tips: Enter voltage in volts, current in amperes, and power factor (0 to 1). For DC circuits or purely resistive AC loads, use PF=1.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between real power and apparent power?
A: Real power (watts) does actual work, while apparent power (VA) is the product of voltage and current. The ratio is the power factor.

Q2: When should I use a power factor less than 1?
A: For AC circuits with inductive (motors, transformers) or capacitive loads where current and voltage are out of phase.

Q3: What's a typical power factor value?
A: Residential: 0.95-1.0, Industrial: 0.7-0.9. Motors at full load: ~0.85, at no load: ~0.2.

Q4: How does power factor affect energy bills?
A: Utilities may charge penalties for low power factor (<0.9) as it increases current requirements without delivering more useful power.

Q5: Can power factor be greater than 1?
A: Normally no. Values >1 typically indicate measurement errors or harmonic distortion.