1. What is the Watt to Amps Formula?

The Watt to Amps formula calculates electrical current (amperes) from power (watts), voltage (volts), and power factor (unitless). It's fundamental in electrical engineering for circuit design and analysis.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

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

Explanation: The formula shows that current is directly proportional to power and inversely proportional to both voltage and power factor.

3. Importance of Current Calculation

Details: Accurate current calculation is essential for selecting proper wire sizes, circuit breakers, and ensuring electrical safety in both AC and DC systems.

4. Using the Calculator

Tips: Enter power in watts, voltage in volts, and power factor (1 for DC circuits or resistive AC loads). All values must be positive (power > 0, voltage > 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 in AC circuits, representing phase difference between voltage and current.

Q2: When can I assume PF=1?
A: For DC circuits or purely resistive AC loads (like incandescent lights or heaters), PF=1. For inductive loads (motors), PF is typically 0.8-0.9.

Q3: How does this differ for three-phase systems?
A: For three-phase: \( I = \frac{P}{\sqrt{3} \times V \times PF} \). Use our three-phase calculator for those calculations.

Q4: Why is my calculated current higher than expected?
A: This could be due to a low power factor (common with inductive loads) or incorrect voltage input.

Q5: How do I use this for circuit breaker sizing?
A: Always round up to the nearest standard breaker size and consider continuous load derating (80% rule).