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, contractors, and facility managers 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)
• \( \sum P_{load} \) — Total electrical load (watts)
• \( SF \) — Safety factor (typically 1.25 for residential use)

Explanation: The total load in watts is converted to kilowatts (divided by 1000) and 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 during outages, prevents overload conditions, and maximizes fuel efficiency.

4. Using the Calculator

Tips: Enter the total wattage of all appliances/equipment you need to power simultaneously and the safety factor (default 1.25). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: Why do we need a safety factor?
A: The safety factor accounts for startup surges (especially for motors) and provides capacity for future additions.

Q2: What's a typical safety factor?
A: Residential: 1.25, Commercial: 1.5, Industrial: 1.75-2.0 depending on criticality.

Q3: How do I find my total load?
A: Sum the wattage of all devices you'll run simultaneously, or use our Load Calculator tool.

Q4: Should I size for continuous or peak load?
A: The calculator accounts for both - enter your continuous load and the safety factor handles peaks.

Q5: Does this include three-phase considerations?
A: No, this is for single-phase loads. For three-phase systems, multiply the result by √3 (1.732).