1. What is a Generator Size Calculator?

Definition: This calculator estimates the required generator size in kilowatts based on the total electrical load and a safety factor.

Purpose: It helps homeowners, businesses, and contractors determine the appropriate generator capacity for their power needs.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( P_{kW} \) — Generator size (kilowatts)
• \( \Sigma P_{load} \) — Total electrical load (watts)
• \( SF \) — Safety factor (typically 1.2-1.5)

Explanation: The total load in watts is converted to kilowatts (divided by 1000) then multiplied by a safety factor to account for startup surges and future expansion.

3. Importance of Proper Generator Sizing

Details: Correct generator sizing ensures reliable power supply, prevents overload conditions, and optimizes fuel efficiency.

4. Using the Calculator

Tips: Enter the total wattage of all connected loads and a safety factor (default 1.2). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: How do I determine my total load?
A: Sum the wattage of all devices that will run simultaneously. Check appliance labels or use our Load Calculator tool.

Q2: What safety factor should I use?
A: Typically 1.2 for residential, 1.3-1.5 for commercial/industrial with motor loads.

Q3: Should I include startup currents?
A: The safety factor accounts for this, but for large motor loads, you may need to calculate separately.

Q4: What about future expansion?
A: Increase the safety factor (e.g., 1.3-1.5) if anticipating additional loads.

Q5: How does this relate to generator ratings?
A: Choose a generator with a continuous rating equal to or greater than your calculated kW.