1. What is a Home Generator Size Calculator?

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

Purpose: It helps homeowners and professionals determine the appropriate generator capacity for backup power needs.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( P_{kW} \) — Generator size (kilowatts)
• \( \sum P_{load} \) — Total electrical load (watts)
• \( SF \) — Safety factor (typically 1.2 for residential)

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

3. Importance of Proper Generator Sizing

Details: Correct sizing ensures your generator can handle all critical loads without being overloaded, while avoiding unnecessarily large and expensive units.

4. Using the Calculator

Tips:

• Calculate your total load by adding wattages of all essential appliances
• Use default safety factor of 1.2 for most residential applications
• For motor-heavy loads (AC units, pumps), consider higher safety factors (1.5-2.0)

5. Frequently Asked Questions (FAQ)

Q1: What's included in total load calculation?
A: Sum the wattages of all appliances you want to power during an outage (lights, fridge, furnace, etc.).

Q2: Why is a safety factor needed?
A: It accounts for startup surges (especially for motors) and provides capacity for future additions.

Q3: What's a typical safety factor?
A: 1.2 for general residential use, 1.5 for homes with central AC, 2.0 for commercial applications.

Q4: Should I round up the generator size?
A: Yes, generators are typically sold in standard sizes (5kW, 7.5kW, 10kW, etc.) - round up to nearest available size.

Q5: How do I find appliance wattages?
A: Check nameplates, manuals, or use our Appliance Wattage Calculator tool for common devices.