Whole House Generator Cost in 2026: Real Installed Prices by Size
By The BackupSizer Team · Published 2026-08-02 · Last verified
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I priced whole-house generators the way I size them: from published numbers, not vibes. Equipment prices below come from manufacturer listings pulled on August 2, 2026. Installed totals come from three independent installer cost guides plus retail bundle listings. Where sources disagree, I show the spread instead of picking a flattering number.
Short version: most homes land between $9,000 and $16,000 installed. Small (10-14 kW) installs run $7,000-11,000. The biggest air-cooled class (26 kW) runs $13,000-19,500. High-cost metro areas blow past all of these.
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| Size class | Equipment only | Installed total | Who it fits |
|---|---|---|---|
| 10-14 kW | $2,500-5,500 | $7,000-11,000 | Gas-heated homes backing up essentials + AC with a soft starter |
| 18-24 kW | $4,200-7,000 | $9,000-16,000 | Most whole-house installs; the 22 kW cluster quotes at $10,000-14,500 |
| 26 kW | $6,500-8,200 | $13,000-19,500 | Large or all-electric homes, usually with load management |
Two honest caveats about that table. First, these are national clusters — California and other high-labor markets report $17,000-26,000 for the middle band. Second, one cost-guide site (ProjectCostPro) runs $3,000-8,000 higher than everyone else across all bands; I treat it as a full-scope upper bound, not the typical case.
What the equipment itself costs (August 2026 MSRPs)
Manufacturer list prices for the current air-cooled lines, unit only:
| Size | Generac Guardian | Kohler (RCA series) | Cummins QuietConnect |
|---|---|---|---|
| 10 kW | $3,649-4,269 | — | — |
| 13-14 kW | $4,569-5,389 | ~$4,900-6,000 street | $4,286 (RS13A) |
| 17-18 kW | $5,379-6,229 | — | $5,290 (RS17A) |
| 20-22 kW | $6,119-6,979 | $5,699 street (20RCA) | $5,748-6,662 (RS20A/AC) |
| 24-26 kW | $6,559-7,899 | $7,299 street (26RCA) | — |
Retail bundles undercut MSRP: at the time of verification, a Generac 26 kW with a 200 A transfer switch listed at Lowe's for about $7,015. If you're comparing brands, the spec differences matter more than the sticker — my Generac vs. Kohler and Generac vs. Cummins breakdowns put the spec sheets side by side.
Installation line items — where the other half of the money goes
The unit is roughly half the project. Here is what the rest buys, with the ranges the cost guides agree on:
| Line item | Typical range |
|---|---|
| Install labor (electrical, placement, commissioning) | $1,500-6,000 |
| Automatic transfer switch hardware (often bundled with the unit) | $500-1,500 |
| Transfer switch install labor | $1,500-3,500 |
| Gas line run (natural gas) | $500-2,000 (~$15-50 per linear foot) |
| Propane setup with tank | $800-2,500 |
| Concrete or composite pad + site prep | $300-1,200 |
| Permit + inspection | $100-500 |
The single biggest quote-to-quote swing is the gas line. Twenty feet from the meter is a rounding error; a hundred feet around a finished patio is a $2,000 line item. When installers quote you wildly different totals for the same unit, this is usually why — get the routing explained before assuming someone is padding the bill.
What the installation actually involves
Knowing the sequence helps you read a quote. A standard air-cooled install breaks into five stages:
- Site work. The unit needs a pad — pre-cast composite or poured concrete — placed to meet clearance rules from windows, doors, and gas meters (manufacturer install manuals specify these; your inspector enforces them). That's the $300-1,200 site-prep line.
- Gas work. A licensed gas fitter runs and pressure-tests the fuel line, and often upsizes the meter — air-cooled units pull a lot of gas at full load (the 26 kW draws 333 ft³/hr, more than a typical furnace and water heater combined). Meter upgrades are usually the utility's work and sometimes free; ask.
- Electrical work. The transfer switch goes between the meter and your main panel (whole-house transfer) or as a sub-panel feed. This is the $1,500-3,500 electrical-labor block.
- Permits and inspection. Electrical and gas permits, then inspection. $100-500 in most jurisdictions.
- Commissioning. First start, load test, exercise schedule, and Wi-Fi monitoring setup. Usually rolled into install labor.
Timeline reality: the work itself is one to two days, but permit turnaround and installer backlogs stretch projects to weeks — and to months regionally after a major storm event, when everyone in your zip code calls the same three dealers.
How to compare quotes without getting played
Three rules make quotes comparable:
Fix the size first. If one installer quotes 22 kW and another 26 kW for the same house, you are not comparing installs — you are comparing load calculations. Run the calculator so you walk in knowing the size class your loads support, then ask each installer to quote that class (or explain, with numbers, why not).
Demand line items. A single bundled figure hides where the money goes. The table above is your checklist: unit, transfer switch, electrical labor, gas line with footage, pad, permit. An installer who won't itemize is telling you something.
Check what the warranty actually needs. All three major brands warrant these units for five years, but warranty service requires documented maintenance. If the quote includes a "free first year" service plan, that's $250-600 of real value; price it in.
Fuel: the derate nobody mentions and what running it burns
Air-cooled units are rated on propane. On natural gas, most derate: Generac's 24 kW produces 21 kW on NG (a 12.5% cut, straight from the spec sheet), the 26 kW produces 22.5 kW, and the 22 kW produces 19.5 kW. The 14 kW is the exception — same rating on both fuels. If your load calculation is tight, size against the NG number, not the sticker.
Burn rates at full load, from the Generac spec sheets: the 18 kW draws 247 ft³/hr of natural gas, the 26 kW draws 333 ft³/hr. On propane, the 22/24 kW classes burn about 3.9 gal/hr flat out — a 500-gallon tank at 80% usable fill is roughly four days of continuous heavy running. Apply your local gas rate to those figures; I won't invent a national average.
The calculator does this fuel math for your tank size and outage length automatically.
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Budget for maintenance or the warranty conversation gets awkward: annual service contracts run $250-600, a one-off service visit $150-450, and a DIY oil/filter kit about $25-40 per year plus your Saturday morning. All three brands warrant these units for 5 years (Kohler and Cummins cap at 2,000 hours). The full ownership math — including what fails at year 8 — is in the maintenance cost guide.
When a standby generator is the wrong purchase
I built a three-way calculator precisely because this category gets oversold. Two honest exits:
Short, rare outages with no natural gas. A battery stack covers a 12-hour outage silently, with no permits for the plug-in class and no annual service. The math is in battery backup vs. generator.
Tight budget, manual operation is fine. A 9,500-watt portable plus a code-legal interlock kit installs for $1,100-2,600 all-in — under a fifth of the cheapest standby install. The tradeoff is you operating it: start, cord, refuel. That path is detailed in portable generator for house backup.
If you have gas at the meter, outages that last days, and no appetite for manual anything — that's the standby profile, and the table above is your budget.
Frequently asked questions
How much is a whole house generator for a 2,000 sq ft house?
Most 2,000 sq ft gas-heated homes compute to a 14-18 kW unit, which lands in the $9,000-16,000 installed band as of August 2026. The house's loads — not its square footage — decide the size; an all-electric 2,000 sq ft home can need 24-26 kW.
Why do installed quotes vary so much for the same generator?
The unit price is public; the site work isn't. Gas-line distance, panel location, pad work, and local permit costs swing the total by thousands. A 22 kW unit with the meter next to the panel can install for $10,000; the same unit across the house in a high-cost metro can pass $20,000.
Is a whole house generator worth the cost?
It depends on your outage profile and fuel situation. With natural gas at the meter and day-plus outages a few times a year, it is the only set-and-forget option. For rare, short outages, a battery or a $1,100-2,600 portable-plus-interlock setup covers most of the value at a fraction of the price.