1. What is Backup Wattage Calculation?

The backup wattage calculation determines the minimum generator capacity needed to power essential household loads during an outage, with a 10% safety margin included.

2. How Does the Calculator Work?

The calculator uses the backup wattage formula:

Where:

• Essential Loads Watts — Total wattage of appliances you need to power during an outage
• 1.1 — 10% safety margin factor

Explanation: The 10% margin accounts for startup surges and ensures your generator isn't operating at maximum capacity continuously.

3. Importance of Proper Generator Sizing

Details: Correct generator sizing prevents overload (which can damage both generator and appliances) while ensuring all essential loads can operate simultaneously.

4. Using the Calculator

Tips: Add up the wattage of all essential appliances (refrigerator, lights, etc.) you want to power during an outage. Enter the total in watts.

5. Frequently Asked Questions (FAQ)

Q1: What counts as "essential loads"?
A: Typically includes refrigerator, lighting, furnace blower, sump pump, and medical equipment. Exclude non-essentials like air conditioning.

Q2: Why the 10% safety margin?
A: Accounts for startup surges (especially motors) and prevents generator from running at 100% capacity continuously.

Q3: How do I find appliance wattage?
A: Check appliance labels or manuals. For motors, use "starting wattage" which is higher than running wattage.

Q4: Should I round up the generator size?
A: Yes, generators are sold in standard sizes. Choose the next available size above your calculated wattage.

Q5: What about whole-house generators?
A: This calculator is for essential loads only. Whole-house systems require professional load calculation.