Generator FAQs

What is Generator Sizing?

Generator sizing is the process of calculating the correct power capacity (measured in kilowatts or kW) needed for a backup generator to safely and effectively power your home or business during an outage. This calculation accounts for your total electrical load—including all appliances, HVAC systems, lighting, and equipment you want to operate simultaneously—plus additional capacity for motor startup surge requirements. Proper sizing ensures your generator can handle your electrical demand without overloading, while avoiding the inefficiency and increased costs of an oversized system.

Professional generator sizing involves analyzing your electrical panel, identifying critical loads, measuring actual amperage draw, and calculating surge capacity requirements for motors in air conditioners, well pumps, and refrigerators. Residential generators typically range from 10-48 kW, with most homes requiring 14-24 kW depending on square footage, climate control needs, and whether you want whole-home coverage or essential circuits only. Undersized generators will overload and shut down during outages, while oversized units waste money on unnecessary capacity and fuel consumption.

Frequently Asked Questions