Generator Sizing Calculator

Find the right backup generator for your home. Select the appliances you need to power during an outage, and this calculator will recommend the most affordable generator that can handle both running and starting loads.

Appliance Counts

Refrigerator (700W)

Sump Pump (800W)

Well Pump (1000W)

Central AC (3500W)

Window AC (1200W)

Furnace Blower (800W)

Additional Loads

Lights (watts)

Misc (watts)

Generator Pricing (edit to match local rates)

Portable 3500W ($)

Portable 7500W ($)

Standby 10kW ($)

Standby 20kW ($)

Standby 24kW ($)

Total Running Watts

2,300W

All appliances running

Total Starting Watts

4,400W

Includes 2,100W starting surge

Recommended

Portable 7,500W

$1,800.00 (cheapest that meets load)

Purchase Option	Quantity	Est. Cost
Portable 3,500W	-900W short	$800.00
Portable 7,500WBest value	+3,100W headroom	$1,800.00
Standby 10kW	+5,600W headroom	$4,500.00
Standby 20kW	+15,600W headroom	$7,500.00
Standby 24kW	+19,600W headroom	$9,500.00

Recommended: Portable 7,500W ($1,800.00)A portable 7,500W generator handles your load with room to spare. Good for moderate backup needs without the cost of a standby unit.

This is a sizing estimate only. Actual generator requirements depend on motor efficiency, altitude, temperature, and simultaneous startup patterns. Always consult a licensed electrician before purchasing and installing a generator.