GeneratorCalc

Free calculators for backup power

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Generator Wattage Calculator (Starting Watts)

Many motor-driven appliances draw more power for a few seconds when they start.

Use this calculator to add up running and starting watts across several loads so you can pick a generator that can handle the combined surge.

Starting vs running watts

List a few appliances and compare total running watts to estimated starting (surge) watts.

Enter up to five appliances. If you do not know starting watts, the calculator can assume about 2× running watts as a rough default.

For more planning tools, you can also use the other calculators and guides on the GeneratorCalc home page.

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