Generator Sizer

Residential Generator Sizer

Select the appliances, equipment, and systems that are important to you during a power outage. As you make selections, the calculator will estimate the generator size that may be needed to power your home.

Feel free to experiment with different combinations of loads to see how your backup power needs affect generator size.

This calculator is intended as a planning tool only. Actual generator sizing should be confirmed during an on-site consultation. We recommend having a qualified backup power professional perform a thorough evaluation of your home's electrical loads, fuel supply, transfer equipment, and installation requirements before making a final generator selection.

1. Home Details

The calculator starts with general lighting and receptacle load, then adds small appliance and laundry circuits.

Net Finished Square Footage

Fuel Type

Small Appliance Circuits

Laundry Circuits

2. Fixed Appliances & Residential Loads

Select the loads you want considered for standby power. Actual nameplate ratings may vary.

Electric Water Heater 4.5 kW typical running load

Electric Clothes Dryer 5.5 kW typical running load

Electric Range / Stove 8 kW typical cooking load

Hot Tub 10 kW typical running load

Dishwasher 1.5 kW typical running load

Built-In Microwave 1 kW typical running load

Well Pump 2 HP / 2 kW running / 6 kW starting

Sump Pump 0.5 HP / 0.5 kW running / 1.5 kW starting

Freezer 0.75 kW running / 2.3 kW starting

Septic Grinder 0.75 kW running / 2.3 kW starting

Garage Door Opener 0.5 kW running / 1.5 kW starting

Kitchen Small Load 1.5 kW typical fixed kitchen load

3. Heating & Cooling

The calculator uses the largest heating or cooling load. For motor-starting, it checks only the largest cycling motor. Non-motor loads stay separate from the motor-starting portion.

Central A/C Size

Second A/C or Heat Pump

Electric Heat / Heat Strips

Your Backup Power Starting Point

â€”

Residential Load Calc â€”

Load Summation Total â€”

Largest Motor Start â€”

Typical installed price: Many residential installs fall around $13,000, with common projects ranging from $12,000â€“$16,000 depending on site conditions, transfer equipment, gas requirements, and coverage goals.

Financing options are available, with payments starting as low as approximately $150 per month for qualified buyers.

This is a planning estimate only. Final sizing should be confirmed using actual appliance nameplate data, locked-rotor amps, fuel supply, load management, transfer switch requirements, installation conditions, and local code requirements.

Ready for an Exact Recommendation?

This estimate is a stronger starting point, but every installation is different. Schedule a free consultation and we'll help determine the right backup power solution for your home.

We don't sell generators. We sell reliable backup power.

Commercial Backup Power

Commercial generators require special consideration for starting loads, three-phase equipment, life-safety systems, code requirements, fuel supply, and business continuity goals. Because every facility is different, we recommend scheduling a consultation with our team.

This calculator is intended for residential lead capture and early education, not final design. It uses common residential load values and simplified load-calculation logic. Always verify final sizing with field data and manufacturer documentation.