Generator sizing calculator

Check what you need to run. Running total + biggest starting surge + 20% headroom = the rating to look for.

kitchen

hvac

essentials

medical

laundry

rv

workshop

Check appliances above — running total, peak demand and a recommended rating appear here.

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Sizing rule: running total + the single largest starting surge, + 20% headroom. Sources on the methodology page. Your nameplate is authoritative.