Where the Money Goes
A full standby installation has five real cost centers: the generator itself, the automatic transfer switch, site prep (pad), fuel supply (gas line or propane tank), and labor/permits. Homeowners are often quoted a single "installed" number without seeing this breakdown — knowing each piece helps you spot an inflated quote or negotiate line items. This estimator treats equipment price, transfer switch, pad, fuel connection, and labor/permits as separate line items rather than a single bundled figure, matching how licensed installers actually build a quote.
Generator Equipment
Priced by kW size class. This is the manufacturer's unit cost — treat any number as a band, not a fixed price, since retail pricing and dealer markups vary.
Transfer Switch
An automatic transfer switch is standard equipment on a standby install, sized to your service amperage and the number of circuits it needs to cover — larger systems need a larger, pricier switch.
Electrical Work & Labor
Scales loosely with generator size and includes running wiring from the transfer switch to your panel and the generator, plus the electrician's time. Site accessibility (how far the generator sits from the panel) is a major swing factor here.
Fuel Connection
Tapping an existing natural gas line is the cheapest path. A new gas line run, or a propane tank and dedicated line if you don't have gas service, costs meaningfully more — this is one of the biggest sources of quote-to-quote variation.
Pad & Site Prep
Most standby units ship with a composite pad included. A poured concrete pad, if your site or local code requires one, adds materials and labor cost.
Permits & Inspection
Most jurisdictions require a permit for a standby generator install, given the electrical panel and gas-line work involved, plus an inspection once installation is complete.
Why Installed Cost Isn't the Same as Equipment Price
Manufacturer and dealer sites frequently show the generator's MSRP prominently, since it's the smaller, more attractive number. That figure is the equipment alone — it doesn't include the transfer switch, the pad, the fuel connection, the electrical labor, or permits, all of which are necessary to actually put a working system in your home. When comparing a quote against this estimator's total, make sure you're comparing installed cost to installed cost, not equipment price to installed cost.
Typical Total Installed Cost by System Size
Based on this calculator's own line-item assumptions, a smaller 10–14 kW system with an existing gas hookup and no poured pad typically lands in roughly the $6,000–$8,000 installed range. A mid-size 16–20 kW system under the same conditions typically lands around $7,500–$10,000, and a larger 22–26 kW system typically runs $10,000–$13,000. Needing a new gas line or a propane tank instead of an existing natural gas hookup, or a poured concrete pad instead of the composite pad most units ship with, pushes any of these ranges higher — which is exactly why the calculator above breaks each of those choices out as a separate input rather than baking them into one number.
Red Flags in an Installer Quote
A few patterns are worth watching for when you're comparing quotes: a single lump-sum number with no itemization at all; a price that seems unusually low relative to others, which sometimes signals a missing line item (like the pad or permit) that gets added later as a "surprise"; and pressure to sign the same day without time to compare at least one other quote. A legitimate installer should be able to walk you through equipment, transfer switch, pad, fuel connection, labor, and permit costs as distinct items on request.
Frequently Asked Questions
The generator unit itself is typically only about half of the total installed cost. The rest is the automatic transfer switch, electrical labor to tie into your panel, a pad or foundation, the fuel connection (gas line or propane tank), and often a permit and inspection fee. A quote that only shows one number is combining all of these into a single figure.
Running a new gas line means trenching or routing pipe from your meter or propane tank to the generator's pad location, which can involve breaking through concrete, going under landscaping, or running a longer distance than expected. An existing line that already reaches near the generator's planned location is far cheaper to tap into than building a brand-new run.
Yes, when you select propane as your fuel source the estimate factors in typical propane-tank-and-hookup costs, which usually run higher than tapping an existing natural gas line since it can include tank rental or purchase, delivery setup, and a dedicated gas line from the tank to the generator.
Most jurisdictions require a permit for standby generator installation because it involves connecting to your home's main electrical panel and often a gas line. Skipping a required permit can create problems later — with insurance claims, a home sale, or an inspector finding unpermitted work. A licensed installer will typically know your local requirement and can pull the permit as part of the job.
It's common for quotes on the same job to vary meaningfully based on labor rates, site accessibility, and how a company bundles line items. Getting quotes from at least three licensed installers, and asking each to itemize equipment, transfer switch, pad, fuel connection, and labor separately, makes it much easier to spot an inflated number or negotiate a specific line item.