Selected manufacturer planning examples

Appliance example Running W Total starting W Additional starting W
Energy Star refrigerator/freezer 132–192 1,200 1,008–1,068
Microwave with 650 W cooking rating 1,000 1,000 0
Electric dryer 5,400 6,750 1,350
Window AC, 10,000 BTU 1,500 2,200 700

The first two numeric columns are approximate examples from Honda’s wattage estimation guide, checked September 4, 2026. The last column is our subtraction. These are not limits or specifications for your appliances. Cooking output is not the same as electrical input.

Avoid counting the same running watts twice

For an illustrative load with 800 W running and 1,300 W total starting demand, the additional starting demand is 500 W. If all planned running loads total 2,000 W, a single-start scenario is 2,000 + 500 = 2,500 W before any planning margin. Adding the entire 1,300 W to that running total would count this appliance’s 800 W twice.

This example assumes one relevant start at a time. Multiple motors starting together, voltage requirements, generator transient performance and fuel-specific ratings can change the result. Use the sizing guide to understand those limits.

Collect better inputs

Record the appliance model, electrical input, voltage and any documented startup requirement. Use manufacturer documentation and qualified measurements when the load is uncertain. Do not open electrical equipment to take measurements yourself.

A utility bill describes energy over time. It does not tell you the peak combination of loads the generator must support. Likewise, a breaker’s rating is not a measurement of the appliance’s operating demand.

Put the chart to work

Enter your own values in the generator size calculator and mark which appliances must operate together. Take the downloaded worksheet to your installer. For equipment that often determines the final system, use the dedicated well-pump guide and central-air guide.

How should uncertain wattage values be labeled?

Mark each wattage entry as a manufacturer specification, measured value or planning estimate. Keep the source and appliance model beside it. Treat central AC and pumps as separate verification tasks when startup information is missing; the well-pump sizing guide explains the inputs that a simple chart cannot settle.