Last verified: October 1, 2026
An air-cooled home standby generator typically costs $5,000–$8,000 installed for a 7–10 kW unit and up to $7,500–$17,000 for a 22–25 kW unit. The generator itself is usually less than half of the bill; installation, the transfer switch and the fuel connection make up the rest.
Installed cost by generator size
| Generator size | Unit price | Estimated installed total* | What it usually powers |
|---|---|---|---|
| 7–10 kW | $2,000–$3,000 | $5,000–$8,000 | Essentials: fridge, sump or well pump, furnace, lights, outlets |
| 13–16 kW | $3,000–$4,500 | $6,000–$9,500 | Essentials plus a small AC or several large appliances |
| 17–20 kW | $4,000–$6,000 | $7,000–$11,000 | Most of a mid-size home, including a 3-ton central AC |
| 22–25 kW | $4,500–$12,000 | $7,500–$17,000 | Whole-home coverage for larger homes, 4–5 ton AC |
Unit prices: HomeGuide generator cost data (2026). *Installed totals are our estimate: the unit price plus HomeGuide’s typical $3,000–$5,000 installation cost. “What it powers” is our guidance based on typical appliance loads; use our size calculator for your own home.
Where the money goes
- The generator itself: $2,000–$12,000, depending on size, brand, Wi-Fi monitoring and enclosure material.
- Automatic transfer switch: $600–$2,500 installed; whole-home (200 A) switches cost more than essential-circuit switches.
- Electrical labor: $3,000–$5,000 for a full installation, depending on the distance to the panel, any panel upgrades and local labor rates.
- Concrete pad: $150–$400, though many units ship with a composite pad.
- Gas line or propane tank: $12–$25 per foot of gas line, or $400–$1,800 to install a propane tank, plus any meter upgrade or tank purchase or lease.
- Permits and inspection: $80–$450, often for both electrical and gas or mechanical work.
All ranges from HomeGuide (2026).
What it costs to run, by size
Fuel use rises with size, but not in a straight line: a lightly loaded big generator can burn less than a small one working hard. Manufacturer figures for Generac’s Guardian air-cooled range at half load, from the Guardian Series brochure, priced at $15 per 1,000 cubic feet of natural gas and $2.67 per gallon of propane:
| Model size | Natural gas at ½ load | NG cost per day | Propane at ½ load | LP cost per day |
|---|---|---|---|---|
| 10 kW | 101 cu ft/h | About $36 | 0.97 gal/h | About $62 |
| 14 kW | 195 cu ft/h | About $70 | 1.81 gal/h | About $116 |
| 18 kW | 169 cu ft/h | About $61 | 1.70 gal/h | About $109 |
| 22 kW | 228 cu ft/h | About $82 | 2.53 gal/h | About $162 |
| 24 kW | 203 cu ft/h | About $73 | 2.53 gal/h | About $162 |
Figures vary between model generations; check the spec sheet of the exact model you are quoted. Fuel prices: EIA national averages; yours may differ.
How to keep the price down
- Size for what you really need. Dropping from 22 kW to 14 kW with an essential-circuits switch can save thousands.
- Ask about a soft starter for the AC. It can lower the start-up surge enough to allow a smaller generator.
- Place the generator close to the gas meter and electrical panel. Shorter runs mean less labor and material.
- Get three itemized quotes. Compare line by line: unit, switch, pad, gas, electrical, permits.
- Buy outside storm season. Late winter and spring are quieter for installers than late summer.
Worked example: two quotes for the same home
A 2,400 sq ft house with a 3-ton AC on natural gas gets two quotes. Here’s how to read them using HomeGuide’s ranges as a check:
Quote A is a 22 kW whole-house setup: a unit within the $4,500–$12,000 range for 22–25 kW and a 200 A service-rated switch. Everything runs during an outage. Quote B is a 14 kW load-managed setup: a unit within the $3,000–$4,500 range for 13–16 kW and a 200 A smart switch with load management. The AC may pause while big appliances run. Installation labor ($3,000–$5,000), gas line ($12–$25 per foot), pad ($150–$400) and permits ($80–$450) are much the same for both, so nearly all the difference comes from the generator and how much of the house you want to run at once.
The structure of the quotes is the same; the difference is mostly the generator itself. If you can live with short AC pauses, Quote B usually saves thousands. If not, Quote A buys you full comfort. See Generator Load Management.
Price traps to watch for
- Bundle prices without itemization. Ask for each line separately so you can compare.
- “Up to” distances. Some quotes include a fixed length of gas line or wire and charge extra beyond it.
- Meter upgrades left out. Ask whether the utility has confirmed meter capacity.
- Monitoring subscriptions. Check whether remote monitoring is free for the life of the unit.
- Seasonal pricing. Quotes right after a big storm may be higher and lead times longer.
Ongoing costs after installation
Budget for scheduled maintenance (oil and filter every 2 years or 200 hours on Generac air-cooled units, with a bigger service every 4 years), a battery every few years ($70–$300 according to HomeGuide) and fuel during outages and weekly self-tests. Over 15 years, these add meaningfully to the purchase price; ask for a written maintenance price as part of the quote.
Frequently asked questions
Why are quotes so different for the same generator?
The generator is only part of the price. Distance to the gas meter and panel, panel upgrades, pad type, permits, labor rates and whether a maintenance plan is included all vary. Ask for itemized quotes so you can see where the difference is.
Are there tax credits for home generators?
Fossil-fuel standby generators generally don’t qualify for the residential clean energy credit, and that credit itself ended for expenses after December 31, 2025. Some utilities or insurers offer programs or discounts; ask locally.
Is the bigger unit worth it?
The step from about 14 kW to 22 kW often adds a few thousand dollars installed. It is worth it if you want central air during summer outages or have electric heat. If you can live without AC during an outage, a smaller unit covers the essentials just as reliably. Our guide Is a Whole House Generator Worth It? helps you weigh the cost against your outage history.