1. What is the Wattage Formula?

The basic formula for calculating electrical power is P = V × I × PF, where P is power in watts, V is voltage in volts, I is current in amperes, and PF is the power factor (a unitless value between 0 and 1).

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, 0 to 1)

Explanation: For purely resistive loads (like incandescent lights or heaters), the power factor is 1. For reactive loads (like motors or transformers), it's typically less than 1.

3. Importance of Power Calculation

Details: Calculating wattage is essential for determining electrical load, sizing circuits, selecting appropriate wiring, and calculating energy consumption.

4. Using the Calculator

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

5. Frequently Asked Questions (FAQ)

Q1: What if I don't know the power factor?
A: For simple resistive loads like heaters or incandescent lights, use 1. For motors, typical values range from 0.8 to 0.95. Check device specifications.

Q2: How does this differ for DC circuits?
A: In DC circuits, power factor is always 1, so the formula simplifies to P = V × I.

Q3: Can I calculate current from power and voltage?
A: Yes, rearrange the formula: I = P / (V × PF).

Q4: Why is power factor important?
A: It represents the ratio of real power to apparent power. Low power factor means inefficient power usage and may result in utility penalties.

Q5: How accurate is this calculation?
A: It's mathematically precise, but accuracy depends on the precision of your input measurements.