What Size Generator Do I Need for My Home?

A Homeowner’s Guide to Choosing the Right Generac Standby Generator

When the lights go out, the last thing you want is to find out your generator doesn’t cover everything you need. At McCay Southern Generators, we help homeowners across East Tennessee and Western North Carolina find the right-sized Generac standby generator—so you’re never left in the dark.

Why Generator Size Matters

Choosing the right size generator is about more than just convenience—it’s about comfort, safety, and peace of mind. An undersized generator can overload, leading to system failure. An oversized one may cost more than you need to spend.

What Do You Want to #Power?

Start by thinking through your priorities. Do you want to power:

• Just the essentials (fridge, lights, medical equipment)?

• A few key rooms (kitchen, living room, master bedroom)?

• Your whole home—including HVAC, appliances, and internet?

Knowing what’s critical to your lifestyle will help determine the wattage required.

A Quick Sizing Guide

Here’s a rough breakdown of common generator sizes and what they can cover:

• 7kW–10kW: Lights, fridge, phone charger, a few small appliances.

• 11kW–16kW: Essentials + 1 AC unit or heating system.

• 17kW–22kW: Most or all major systems, ideal for medium-sized homes.

• 22kW–26kW+: Whole-home power for larger homes with multiple AC units.

The McCay Advantage: Free In-Home Assessment

Every home is different, and that’s why we offer free, no-obligation assessments. Our team will visit your home, evaluate your electrical panel, ask about your power needs, and recommend the right Generac system for you.

Bonus: Future-Proof Your Investment

Our experts also consider growth—so if you plan to expand your home or add a hot tub, EV charger, or workshop later, we factor that in today.

Not Sure Where to Start? Call us at (423) 455-5336 or schedule your free home assessment today. We’ll make sure you get the power you need—no more, no less.