Power & Generators calculators

Use this category for a permanently installed standby generator, not a portable unit on an extension cord. Cost moves with kW, fuel, how far the unit sits from the meter or tank, and what the installer bundles. A 10 kW unit that covers a few circuits is a different ticket from a 22–24 kW unit sized for central air. HomeGuide’s unit bands rise with size; labor for jobs over 20 kW or with a long gas run is $5,000–$12,000 instead of $3,000–$5,000.

Sizing and cost are not the same question. Oversizing inflates the generator line and can push you into the higher labor band; undersizing leaves loads you cannot run. Use the generator size calculator for a load list (running watts plus the largest motor surge, then a 25% margin rounded to 10–32 kW). Use the cost calculator once you have a kW.

Standby generators are not DIY plug-and-play. Wiring belongs to a licensed electrician. A licensed gas fitter must run a new natural-gas or propane line. Most cities require a permit and inspect the pad, transfer switch, and gas connection. The permit default is a published range, not your city’s fee. Electrical work starts empty; we have no cited lump for that line. Every dollar on the page is editable because region and installer quotes vary.