Quick answer: the typical whole house generator cost lands between $6,000 and $12,000 installed for a mid-size home. That whole house generator cost splits roughly half equipment, half installation, and the sections below break down every line of the whole house generator cost so you can audit any dealer quote. A portable plus transfer switch cuts the whole house generator cost to $2,000-$3,500 for essentials only.
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A whole house generator costs between $2,000 and $25,000 installed. Most homes land between $6,000 and $12,000 all-in. Where you fall in that range depends on three things: the size of the unit, the fuel type, and how much your local installer charges for labor. This guide breaks down each one with real numbers.
Whole house generator cost: equipment by size
The generator itself is usually half to two-thirds of the total project cost.
| Generator size | Typical price (equipment only) | Best for |
|---|---|---|
| 2,000 W portable inverter | $500 - $1,200 | Fridge, lights, internet |
| 5,000 W portable | $600 - $1,500 | Essentials plus a window AC |
| 7,500 W portable | $900 - $2,000 | Most of a small gas-heated home |
| 10,000 W standby | $2,500 - $4,500 | Whole small home, automatic start |
| 16,000 - 22,000 W standby | $4,000 - $8,000 | Whole medium-to-large home |
| 24,000 W+ liquid-cooled | $9,000 - $15,000+ | Large all-electric homes |
Not sure what size you need? Run your appliance list through our generator size calculator first. Sizing mistakes are the most expensive kind: too small and the breaker trips every time the AC starts, too big and you paid thousands for capacity you never use.
Installation: the whole house generator cost most people underestimate
Standby generators need professional installation. This is not a DIY job because it involves gas lines and a permanent electrical connection.
- Transfer switch: $500 - $1,500
- Electrical work and permitting: $1,000 - $3,000
- Gas line connection: $500 - $2,000 (more if you need a new meter or larger supply line)
- Concrete pad: $500 - $1,000
- Labor total: expect $2,000 - $5,000 in most US metro areas
Get at least three quotes. We have seen installation quotes for the same 22kW Generac range from $3,800 to $8,500 within the same county. The difference is rarely quality; it is how busy each shop is.
Portable generators: the budget path
A portable generator with an interlock kit or manual transfer switch avoids most installation cost. A capable 7,500 W dual-fuel portable plus a transfer switch installed runs $2,000 - $3,500 total, versus $8,000+ for an equivalent standby setup.
The tradeoffs are real. You wheel it out and start it yourself during an outage, it runs on gasoline you must store and rotate, and it will not run a central AC. For homes with gas heat in outage-prone regions, though, it covers 90% of what a standby does at a third of the price.
Fuel type affects both price and running cost
Natural gas standby units are the most convenient: they draw from your utility line and run indefinitely. Propane requires a tank (purchase or lease, $400 - $2,000) but works where gas lines do not reach. Diesel is mostly a commercial option now for homes. Portable dual-fuel units that run on gasoline or propane give you flexibility at the cost of manual fuel management.
The costs after the purchase
Budget for these from day one:
- Maintenance: a standby unit self-runs a 12-minute exercise cycle weekly and needs oil and filter service yearly, about $150 - $300 per year if you use a service plan
- Warranty extensions: often $300 - $800, worth considering on $5,000+ units
- Fuel: a 22kW unit at half load burns roughly 100 - 200 cubic feet of natural gas per hour
Ways to spend less
Buy in the off-season. Generator demand spikes after hurricanes and ice storms, and so do prices and lead times. Spring installations are consistently cheaper and faster to schedule.
Also check utility programs. Several state programs and utilities offer rebates for generators installed with automatic transfer switches, particularly in the Northeast and Gulf Coast states. $500 to $1,000 back is common where programs exist.
Where to buy
Equipment is only half the whole house generator cost; compare street prices before you get dealer quotes: whole house generators on Amazon, or the budget path via the Westinghouse WGen7500DF portable.
FAQ
Is a whole house generator worth the money? If your area gets multi-day outages regularly, or someone in the house depends on powered medical equipment or a well pump, the answer is usually yes. If outages are rare and brief, a $1,000 portable covers the fridge and internet for a fraction of the cost.
How long does installation take? The physical install takes one to two days. Permitting and scheduling add two to six weeks in most jurisdictions.
Can I install a standby generator myself? You can mount the pad and position the unit, but the gas and electrical connections legally require licensed trades in nearly all US jurisdictions, and DIY work voids most warranties.
Bottom line on whole house generator cost
For a typical 2,000 - 2,500 sq ft gas-heated home, plan on roughly $8,000 - $12,000 for a 16 - 22kW standby installed, or $2,000 - $3,500 for a portable-plus-switch setup covering the essentials. Size first with the calculator, then get three local quotes and compare line items rather than totals.
Related: size your load first with the generator size calculator, then see which models land in your budget in the generator comparison.
