Size it to the loads you need
A load calculation should show which circuits the generator will carry. Central air, a well pump and electric cooking drive the size up the most.
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Whole-House Standby · Transfer Switch · Gas Line · Concrete Pad · PermitsStandby generator installation cost calculator
A natural-gas whole-house generator typically costs $6,000 to $11,000 installed. A 17 to 20 kW unit commonly runs $7,000 to $11,000, and a 22 to 25 kW unit $9,500 or more. The generator is only part of the bill: the transfer switch, the gas line, the pad and the permits add several thousand dollars, so ask for each one separately.
Reviewed 25 October 2026 · Written by Mantu Kumar
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Written and maintained byMantu Kumar
Evidence review16 October 2026
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Key facts at a glance
- Natural-gas whole-house setup: about $6,000–$11,000 installed.
- By size: 17–20 kW about $7,000–$11,000 installed; 22–25 kW about $9,500–$24,000.
- Transfer switch installation: about $1,200–$1,600, average near $1,450.
- Gas line: $400–$1,500+; concrete pad: $150–$400; permits often $100–$450 combined.
- Maintenance: about $200–$600 a year for a service visit and parts.
Source: ThePricer standby generator cost roundup (2025–2026 data); ReplaceCost 2026 planning ranges.
2026 planning ranges
- 117–20 kW · $7,000–$11,000 installed
- 2Transfer switch · $1,200–$1,600
- 3Gas line · $400–$1,500+
- 4Main panel tie-in + permits
- 5Concrete pad · $150–$400
- 6Clearances per code & maker
- 7Essentials or whole house
- 8Meter or tank capacity
- 9Service + weekly exercise
Standby generator cost estimator
No email · nothing sentDiagram, part by part
Standby generator installation: every numbered part explained
The standby generator installation drawing above has 9 numbered parts, from 17–20 kW to Yearly service and exercise. Each card below frames one of them, and after you run the calculator it shows what that part adds to your estimate.
1 17–20 kW
$7,000–$11,000 installed
A 17 to 20 kW air-cooled standby generator runs most of a typical house, including central air. Smaller units cover essential circuits only, while large homes or electric heat may need more.
What moves it: The loads you want to run and the generator brand.
On the quote: Ask for a load calculation that lists which appliances can run at once.
2 Transfer switch
$1,200–$1,600
The automatic transfer switch senses an outage, starts the generator and moves the house to generator power within seconds, then switches back when utility power returns.
What moves it: Service size and whether the switch is whole-house or essential circuits.
On the quote: Ask whether the switch is rated for your full service and how it handles large loads.
3 Gas line
$400–$1,500+
A gas line runs from the meter to the generator. Long runs, a meter upgrade from the utility or a propane tank installation add cost.
What moves it: Distance from the meter and the fuel type.
On the quote: Ask for pipe size and length and whether the utility needs to upgrade the meter.
4 Main panel tie-in and permits
$100–$450
The transfer switch ties into the main panel. Electrical and gas permits, and sometimes a utility notification, are part of the job.
What moves it: Your town and utility.
On the quote: Ask who pulls the permits and schedules the inspections.
5 Concrete pad
$150–$400
The generator sits on a level composite or concrete pad, above any flood line and clear of drainage paths.
What moves it: Pad type and site grading.
On the quote: Ask whether the pad is included or supplied by the manufacturer.
6 Clearances per code & maker
Sets the gas and wire lengths
Manufacturers and codes set distances from windows, doors and vents so exhaust does not enter the house. Placement decides the gas and wire lengths and often the price.
What moves it: Your lot, the house layout and local rules.
On the quote: Ask for a site plan showing where the generator goes and the clearances.
7 Size: essentials or whole house
10–14 kW essentials · 17–24 kW whole house
A smaller generator covers the furnace, refrigerator, well pump and some lights. A whole-house unit also runs central air and kitchen loads. Load management can let a smaller unit cover more by switching large loads off in turn.
What moves it: Which appliances must run during an outage.
On the quote: Ask whether a load manager could let a smaller generator do the job.
8 Gas meter or propane tank capacity
Utility may upgrade the meter
A standby generator uses a lot of gas at full load. The utility may need to upgrade the meter, and propane systems need a tank large enough to run for several days.
What moves it: Generator size and your other gas appliances.
On the quote: Ask the installer to check meter or tank capacity before you order the unit.
9 Yearly service and exercise
Ongoing cost
Standby generators run a short self-test every week and need oil, filter and battery service about once a year. Skipping service is the most common reason a unit fails to start in an outage.
What moves it: Run hours and the service plan you choose.
On the quote: Ask about the warranty terms and what yearly service costs.
Size, switch and fuel
Separate a $7,500 essentials setup from an $18,000 whole-house system
Generator quotes differ mostly in size and in what the transfer switch can run. A smaller unit with a load-managed switch can power the essentials; running central air and an electric range at once needs a larger unit.
The three close-ups below show the unit, the wall connections and the clearances to check before you approve a price. These close-ups are crops of the same AI-generated illustration.
Ask what the switch includes
An automatic transfer switch, usually 200 amps for whole-house coverage, is installed at or near the panel. Confirm the gas meter can supply the generator along with the furnace and water heater.
Check clearances before signing
Exhaust clearances from windows, doors and vents, and setbacks from property lines, decide where the unit can go. A unit that cannot be placed legally is not a bargain.
Before you sign a quote or file a claim, verify these three details
- Size and load
- Kilowatt rating and which circuits or appliances it will run
- Transfer switch
- Automatic or manual, amperage, and whether load management is included
- Fuel and pad
- Gas line length, meter capacity, pad and permits
On this page
- 2026 generator cost by size
- The line items in a generator quote
- How big a generator do you need
- Worked example: a 22 kW natural gas install
- Insurance and generators
- Standby generator installation cost by region
- What “Generator size” does to the price
- What “Gas line” does to the price
- How age changes the standby generator installation claim payout
- Quote checklist: 7 items to verify
- How long the job takes
- Common mistakes that raise the cost
- Ways to keep the cost down
- Signs a standby generator makes sense
- Sources
- Frequently asked questions
Standby generator cost by size (2026)
| Size | Installed cost | Typical use |
|---|---|---|
| 13 kW class | From about $3,957 (unit only) | Essentials: fridge, furnace, lights |
| 17 – 20 kW | $7,000 – $11,000 | Most mid-size homes |
| 22 – 25 kW | $9,500 – $24,000 | Larger homes with central air |
| Natural-gas whole-house setup | $6,000 – $11,000 | Common suburban install |
The line items in a generator quote
| Item | Typical cost |
|---|---|
| Transfer switch installation | $1,200 – $1,600 |
| Gas line installation | $400 – $1,500+ |
| Concrete pad | $150 – $400 |
| Electrical permit | $50 – $200 |
| Fuel-line plumbing permit | $50 – $150 |
| Zoning permit | Often under $100 |
| Annual maintenance | $200 – $600 per year |
How big a generator do you need?
Size is driven by the loads you want running at the same time. A refrigerator, furnace fan, lights, internet and a few outlets fit a smaller unit. Central air conditioning, a well pump, an electric water heater or an electric range push toward 20 kW and up. Many installers use a load-managing transfer switch that sheds big appliances when needed, which lets a smaller generator cover more of the house.
Ask the installer for a written load calculation. It is the honest way to compare a 14 kW quote with a 22 kW one.
Worked example: a 22 kW natural gas installation
These are the calculator’s default inputs: an 18–24 kW air-cooled unit, natural gas run of moderate length, new pad and automatic transfer switch, national pricing.
22 kW natural gas · 200A transfer switch
Worked example| Line item | 2026 planning range |
|---|---|
| 18–24 kW generator with 200A transfer switch (unit) | $6,000 – $9,000 |
| Transfer switch installation | $1,200 – $1,600 |
| Gas line to the pad | $400 – $1,500 |
| Concrete pad | $150 – $400 |
| Permits | $100 – $450 |
| Planning total | $7,850 – $12,950 |
The source’s worked 22 kW example totals $9,764, near the middle of this range. Long gas runs, a meter upgrade or a panel upgrade would add to it.
Insurance and standby generators
- Buying a generator is not a claim. It is a home improvement.
- A permanently installed generator is usually treated as part of the dwelling or other structures, so damage to it from a covered peril may be covered. Check your policy.
- Some insurers offer discounts for standby generators because they help prevent frozen pipes, sump pump failures and food loss during outages.
- Power outages themselves are generally not a covered cause of loss, which is one reason a generator can pay for itself.
Standby generator installation cost by region
The calculator's default standby generator installation job, repriced for each of its six regions. At the national average it runs $7,850 – $12,950; South / Lower Midwest is the lowest at $6,830 – $11,267, and West Coast metro is the highest at $10,205 – $16,835, a gap of about $4,472 at the midpoint.
| Region | Planning range | Midpoint |
|---|---|---|
| National average | $7,850 – $12,950 | $10,400 |
| South / Lower Midwest | $6,830 – $11,267 | $9,048 |
| Mountain / Plains | $7,458 – $12,303 | $9,880 |
| Mid-Atlantic / Upper Midwest | $8,792 – $14,504 | $11,648 |
| Northeast metro | $9,891 – $16,317 | $13,104 |
| West Coast metro | $10,205 – $16,835 | $13,520 |
What “Generator size” does to the price
Every other input stays at its default and only “Generator size” changes. The cheapest choice, 10–14 kW air-cooled (essentials), comes to $5,350 – $9,950; the most expensive, 18–24 kW air-cooled, comes to $7,850 – $12,950.
| Choice | Planning range | Midpoint vs default |
|---|---|---|
| 10–14 kW air-cooled (essentials) | $5,350 – $9,950 | −$2,750 |
| 17–20 kW air-cooled | $6,850 – $11,950 | −$1,000 |
| 18–24 kW air-cooled (default) | $7,850 – $12,950 | — |
What “Gas line” does to the price
Every other input stays at its default and only “Gas line” changes. The cheapest choice, Short run, meter close by, comes to $7,850 – $12,250; the most expensive, Long trenched run, comes to $8,950 – $13,950.
| Choice | Planning range | Midpoint vs default |
|---|---|---|
| Short run, meter close by | $7,850 – $12,250 | −$350 |
| Moderate run (default) | $7,850 – $12,950 | — |
| Long trenched run | $8,950 – $13,950 | +$1,050 |
How age changes the standby generator installation claim payout
Using the default job, a $1,000 deductible and a 20-year expected life. At 10 years old, about $5,200 is held back as depreciation; a replacement cost policy releases it after the work is finished, while an actual cash value policy keeps it.
| Age | Wear | First check | Held back |
|---|---|---|---|
| 2 years | 10% | $8,360 | $1,040 |
| 5 years | 25% | $6,800 | $2,600 |
| 10 years | 50% | $4,200 | $5,200 |
| 15 years | 75% | $1,600 | $7,800 |
| 20 years | 80% | $1,080 | $8,320 |
| 30 years | 80% | $1,080 | $8,320 |
Quote checklist: 7 items to verify
Standby generator quotes differ most in the work around the unit.
- Load calculation. Which circuits and appliances the generator will run at once.
- Generator model and size. kW rating on natural gas or propane, which can differ.
- Transfer switch. Whole-house or essential circuits, with amperage.
- Gas line. Pipe size, length and any meter or tank upgrade.
- Pad and placement. Pad type and clearances from windows, doors and vents.
- Permits and inspections. Electrical, gas and any zoning or noise rules.
- Startup and service. Commissioning, first-year service and warranty registration.
How long the job takes
| Stage | Typical time | What happens |
|---|---|---|
| Site visit and load check | 1 – 2 hours | Placement, gas meter and panel review. |
| Permits | 1 – 4 weeks | Electrical and gas permits; some towns need a site plan. |
| Equipment delivery | 1 – 8 weeks | Longer after major storms. |
| Installation | 1 – 3 days | Pad, unit, gas line and transfer switch. |
| Inspection and startup | 1 – 14 days | Inspection, utility sign-off and first run. |
Book the installation before storm season; demand and lead times rise sharply after a regional outage.
Common mistakes that raise the cost
- Guessing the size. Without a load calculation, units end up too small or far too big.
- Ignoring gas capacity. An undersized meter or tank starves the generator at full load.
- Placing it too close. Exhaust near windows and doors is a carbon monoxide risk.
- Skipping the permit. Unpermitted work can cause problems with the utility, insurer or a buyer.
- Never servicing it. Units that miss yearly service often fail when the power goes out.
Ways to keep the cost down
Placement and sizing decide most of the price.
- Place it near the gas meter. Shorter gas line.
- Size to essentials. Smaller unit.
- Use load management. Lets a smaller unit run more.
- Install before storm season. Better scheduling.
- Compare transfer switch options. Essentials or whole house.
- Check rebates or tax rules. Occasionally available.
Signs a standby generator makes sense
These situations favor a standby unit.
- Frequent outages. Reliability.
- Medical equipment at home. Must stay powered.
- Well pump and sump pump. Water and flooding.
- Work from home. Power needed.
- Cold or hot climate. Heating or cooling during outages.
Sources and further reading
- ThePricer — How much does a standby generator cost
- NAIC — Actual cash value vs replacement cost coverage
Frequently asked questions
How much does a whole-house generator cost installed in 2026?
A natural-gas whole-house setup typically costs $6,000 to $11,000. A 17 to 20 kW unit is commonly $7,000 to $11,000 installed, and a 22 to 25 kW unit about $9,500 or more.
How much does a transfer switch cost to install?
Transfer switch installation typically runs $1,200 to $1,600, with an average around $1,450. Load-managing switches cost more but can let a smaller generator run more of the house.
What size generator do I need for my house?
It depends on what you want running at once. Essentials fit a smaller unit; central air, a well pump and electric cooking need 20 kW or more. Ask the installer for a written load calculation.
Do I need a permit for a standby generator?
Usually yes. Expect an electrical permit ($50 to $200), a fuel-line permit ($50 to $150) and sometimes a zoning permit, often under $100.
How much does generator maintenance cost?
Typically $200 to $600 a year for a service visit, oil and filters, and battery checks.
Does homeowners insurance cover a standby generator?
A permanently installed generator is usually covered as part of the home for covered perils. Some insurers also offer a discount for having one.
How loud is a standby generator?
Many home standby units run at roughly the noise level of a central air condenser, and the weekly self-test is often quieter. Placement and local noise rules matter for neighbors.
Can a generator run on propane instead of natural gas?
Most standby units can run on either, but output is usually different on each fuel, and propane systems need a tank large enough for several days of running.
Does a standby generator add home value?
It can appeal to buyers in areas with frequent outages, but it rarely returns its full cost at sale. Most owners buy one for reliability, not resale.
Do I need a carbon monoxide alarm with a standby generator?
Yes. CO alarms should be on every level of the home, especially when any fuel-burning equipment is installed.
How long can a standby generator run?
On natural gas, as long as gas is supplied. On propane, it depends on tank size and load.
Can I install a portable generator instead?
A portable generator with a transfer switch or interlock costs less but must be started manually and run outdoors.
What is an automatic transfer switch?
It senses an outage, starts the generator and switches the home to generator power automatically.
Do generators need oil changes?
Yes. Most units need oil, filter and spark plug service on a schedule set by the maker.
Where can a standby generator be placed?
Usually outdoors on a level pad, a set distance from windows, doors, vents and property lines as required by the maker and local code, and close to the gas meter to keep the gas line short.
Can a generator power central air?
A whole-house unit sized for the load can. Load management modules and soft-start kits help large AC compressors start without overloading the generator.
Do I need to notify my utility?
Some utilities require notice or an inspection for standby generators and transfer switches. The installer usually handles the paperwork along with the permits.
Related planning tools
Next steps for your estimate
The next questions after a standby generator estimate usually land on one of these.
Electrical panel upgrade calculatorMake sure the panel can take a transfer switch.Sump pump calculatorKeep the sump running in an outage.Wiring and outlet calculatorAdd circuits for the generator.HVAC replacement calculatorSize the generator for the AC.Solar panel calculatorCompare backup with solar and batteries.Water heater calculatorCheck gas capacity with other appliances.Well pump calculatorSize the generator for the well pump.EV charger installation calculatorPlan the charger with the panel.
Key topics covered
Popular standby generator searches answered on this page
Planning topics covered in the calculator and guide above.
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