What Size Generator Do I Need for My Home?

• The right generator size depends on how much of your home you want to power.
• Essential-only backup requires less capacity than whole-home coverage. Generator sizes are measured in kilowatts (kW).
• Home size, HVAC systems, and fuel type affect generator needs. A professional load assessment helps ensure accurate sizing and reliable performance.

The right home generator size depends on your home’s electrical load, including essential appliances, heating and cooling systems, and other everyday power needs.

Many homeowners choose to power only the essentials during a power outage. This may include a refrigerator, sump pump, lights, outlets, and a furnace or air conditioner. In these cases, a smaller standby generator may be sufficient. However, if you want whole-home backup power (including central air conditioning, electric water heaters, kitchen appliances, and laundry equipment), you’ll likely need a larger generator with higher wattage capacity.

Generator capacity is measured in kilowatts (kW). Smaller homes with limited backup needs may require 10-14 kW, while larger homes or homes with multiple HVAC systems may need 20 kW or more.

Factors like square footage, fuel type, and whether your home uses natural gas or propane also play a role in determining the best fit.

As a general guideline:

• 10-14 kW: Suitable for smaller homes or essential-circuit backup (refrigerator, lights, furnace, sump pump).
• 14-20 kW: Ideal for mid-sized homes that want to power most major systems, including central air conditioning.
• 20-26+ kW: Designed for larger homes or whole-home backup, especially those with multiple HVAC systems or high-demand appliances.

Because every home is different, a professional load assessment is the most accurate way to determine the right generator size. A certified dealer can evaluate your electrical panel, calculate starting and running wattage requirements, and recommend a system that delivers reliable performance when you need it most.

Choosing the correct generator size ensures your home stays comfortable, connected, and protected during unexpected power outages.

To learn more, visit South Shore Generator Sales & Service.

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