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GEN SIZECALCULATOR

Appliance & Home Size Guides

Generator Size For Every Appliance & Home Size

Detailed generator sizing guides for specific appliances and home sizes. Each guide shows exact running watts, surge watts, recommended generator size, and top picks.

Generator Size by Appliance

Refrigerator
150W running / 600W surge
Sump Pump (½HP)
800W running / 2,400W surge
Well Pump (1HP)
1,500W running / 4,000W surge
Window AC
1,200W running / 3,600W surge
Portable AC
900W running / 2,700W surge
Central AC (2-ton)
2,500W running / 7,800W surge
Heat Pump
3,000W running / 9,000W surge
Space Heater
1,500W running / 1,500W surge
Chest Freezer
100W running / 400W surge
Washing Machine
500W running / 2,300W surge
Arc Welder
3,500W running / 7,000W surge
Air Compressor
1,500W running / 4,500W surge
RV / Camper
1,500W running / 4,500W surge
Off-Grid Cabin
3,000W running / 5,000W surge

Generator Size by Home Size

1,000 Sq Ft House
3,500–5,500W
1,200 Sq Ft House
4,500–6,500W
1,400 Sq Ft House
5,000–7,500W
1,500 Sq Ft House
5,500–8,500W
1,800 Sq Ft House
7,500–10,000W
2,000 Sq Ft House
8,500–12,000W
2,200 Sq Ft House
10,000–14,000W
2,500 Sq Ft House
12,000–16,000W
3,000 Sq Ft House
14,000–20,000W
Sump Pump + Refrigerator
3,500–5,000W

How to Use These Guides

Single-Appliance Sizing

Each appliance guide shows the running watts, surge watts, recommended minimum generator size, and our top portable and standby generator picks for that specific load. If you only need to power one appliance, these pages give you an exact answer in seconds.

Multi-Appliance Sizing

If you need to power multiple appliances simultaneously, add all running watts together — however, only add the highest single surge value, not all surges at once. For multi-appliance calculations, use our free generator size calculator which handles this automatically.

Home-Size Guides

The home-size guides (1,000 sq ft through 3,000 sq ft) estimate your total load based on typical appliances for that home size. They're a useful starting point, but actual requirements vary by your specific appliances, HVAC type, and usage patterns. Furthermore, all-electric homes require larger generators than homes with gas appliances.

Free Tool

Need to Size for Multiple Appliances?

The calculator handles any combination — add all your appliances and get exact running watts, surge watts, and generator size recommendation with the 80% rule applied.

Open Generator Size Calculator

Common Questions