How Much Does a Whole-House Generator Cost in 2025?
Typical Range:
$1,539 - $8,815
Cost data is based on actual project costs as reported by 4,292 HomeAdvisor members. Embed this data
How We Get This Data
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- Homeowners use HomeAdvisor to find pros for home projects.
- When their projects are done, they fill out a short cost survey.
- We compile the data and report costs back to you.
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Updated December 4, 2024
Reviewed by Salvatore Cutrona, Angi Expert Review Board member and founder of Cutrona Electric, LLC, in Sherman, CTWritten by HomeAdvisor.
Highlights
Whole-house generators cost $5,175 on average, with prices typically ranging between $1,539 and $8,815.
Capacity is the main cost factor, with residential units ranging from one kilowatt to 30 kilowatts or more.
Generator fuel types may affect upfront unit costs, installation labor fees, and ongoing fuel costs.
Hiring an electrician to install a whole-house generator costs between $1,500 and $5,000.
Installing a backup generator costs $5,175 on average, with most homeowners paying between $1,539 and $8,815. Generators come in various sizes, configurations, and fuel types, and each factor can influence your final costs. For example, standby whole-house generators range from $5,000 to $25,000 with installation, while emergency portable generators average $1,500 to $6,000.
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| National Average | $5,175 |
| Typical Range | $1,539 - $8,815 |
| Low End - High End | $350 - $13,500 |
Cost data is based on actual project costs as reported by 4,292 HomeAdvisor members.
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Whole-House Generator Cost Factors
Installing a whole-house generator depends on the capacity required, brand, labor rates, and other factors.
Capacity
Generator prices range from $500 to $50,000, depending on capacity. Most models over about 30 kilowatts (kW) require liquid cooling, which adds a few thousand dollars to the base unit price compared to air cooling.
Small homes with one or two bedrooms and several appliances may need a low-end generator, costing about $2,000 to $3,500. Large homes with high energy demands, like multiple refrigerators or heavy-duty HVAC, may need a 20-kilowatt or larger generator.
| Generator Size in kW | Typical Use | Unit Price Range |
|---|---|---|
| 1–6 | Portable backup sizes | $500–$1,800 |
| 7.5–10 | Essential and non-essential systems for homes under 1,500 sq. ft. | $2,000–$3,500 |
| 14–18 | Critical systems for homes ranging from 1,500–3,000 sq. ft. | $4,000–$5,500 |
| 20–24 | Main systems for large homes, 3,000–5,000 sq. ft. | $5,000–$6,500 |
| 26–32 | Main systems for large homes, plus additional appliances and devices | $6,500–$15,000 |
| 36–38 | Large homes with numerous high-demand appliances | $14,000–$16,000 |
| 45–48 | Large homes with numerous appliances, systems, and commercial-grade equipment | $16,200–$21,000 |
| 60–80 | Large whole-house systems with luxury amenities, like a sauna or heated pool | $21,500–$31,000 |
Brand
Brand influences the quality, reliability, features, and total costs of many generators. Well-known brands like Generac or Cummins are popular among homeowners for their reliability, warranties, and customer service. They offer an array of generator models to suit various household needs.
| Brand | Average Cost Range |
|---|---|
| Champion | $400–$2,000 |
| Briggs & Stratton | $2,400–$15,300 |
| Generac | $2,000–$30,000 |
| Cummins | $3,000–$15,000 |
| Honda | $900–$6,000 |
| Kohler | $2,700–$16,000 |
Concrete Pad
Concrete pads for generators cost around $50 to $75 per square foot or $1,000 total for an 18-square-foot pad. Large standby and whole-house generators are permanent installations, so a concrete pad is necessary to protect them from water and other elements that can damage internal components.
Transfer Switch
A transfer switch detects electrical disconnection and switches from the grid power supply to your generator. The National Electric Code requires these devices for safety and backfeeding prevention.
There are several types of power switches. Most residential buildings use either standard manual transfer switches, which range from $500 to $1,300, or automatic transfer switches, which range from $600 to $2,500.
Manual switches require homeowners to physically flip a switch to change the power source. Automatic switches don’t require manual intervention—instead, they seamlessly switch between utility and generator power. The cost for either option depends on amperage and installation complexity.
Labor
Hiring a generator installer in your area to install a permanent home generator costs about $1,500 and $5,000. While not required for portable units, installing a transfer switch and power inlet box also adds to labor costs. Most contractors charge on a per-project basis, but some contractors may add fees based on individual factors, such as:
Energy load assessment
Site preparation
Fuel tank configuration
Gas line connection
Electrical panel upgrade
Transfer switch installation
Wiring and circuits
Permits
Permits cost around $50 to $200 each. Actual costs depend on local pricing and the specifications of your installation. You’ll likely need a permit for both the electrical upgrade and plumbing in a fuel tank or gas line.
Maintenance
Annual generator maintenance service costs about $170 to $400. A regular inspection before the summer and winter (the seasons where you’ll most likely lose power) anticipates and prevents issues to keep your generator running smoothly.
Electrical Upgrades
Some generator installations require changing or upgrading your electrical panel to accommodate the additional power supply. An electrical subpanel costs about $500 to $2,000 and can isolate specific circuits for essential appliances. For large-capacity generators, you may need to replace the main electrical panel to handle increased loads safely.
Enhancements
Generator enhancements can help your unit run more efficiently. Here are a few options to consider:
Wireless monitor ($200–$400): Provides remote generator status monitoring
Smart load manager ($150–$300): Creates different zones to switch the power between them
Remote start and operation ($100–$1,000): Allows you to start or stop the generator via a smartphone app
Generator Cost by Type
Depending on the type and size, you’ll spend approximately $500 to $20,000 for most generators.
Standby
Whole-house or standby generators average $17,000, ranging from $2,000 to $20,000 before installation costs. These permanent installations are hardwired to your home and can automatically power your home when it doesn’t have access to grid power. Depending on your home’s power demand and the size of the generator, a standby generator can power an entire home or just critical systems, such as HVAC, refrigeration, and lighting.
Portable
Portable generators cost about $200 to $6,000. They typically run on either gasoline or diesel and range in size. Small units of around one kilowatt can power critical systems, and larger units of up to 7.5 kilowatts can sometimes power most of a home. Portable units are ideal for short-term needs because they require manual operation.
Generator Fuel Type
The fuel type of a generator affects unit costs, installation fees, and ongoing expenses. Each fuel type has different advantages and drawbacks regarding efficiency, availability, and cost.
| Generator Fuel Type | Average Cost Range | Average Fuel Cost per Day |
|---|---|---|
| Natural gas | $2,000–$21,000 | $90 |
| Liquid propane | $2,000–$21,000 | $220 |
| Diesel | $3,000–$20,000 | $175 |
| Gasoline | $500–$3,000 | $100 |
| Solar | $2,000–$25,000 | $0 |
| Battery backup | $10,000–$25,000 | $0 |
Natural Gas
Natural gas generators cost around $2,000 to $21,000. They’re only available as standby units because they require a permanent natural gas connection. The higher relative cost for a natural gas generator stems from its more complex fuel delivery system, but it offers superior efficiency and convenience over other types. Installation can be more costly, often requiring gas line pressure testing and generator ventilation checks.
Liquid Propane
Propane generators cost about $2,000 to $21,000, and portable options average $600 to $2,600. They’re a popular option for off-the-grid and rural areas without natural gas line infrastructure. Propane generators also require setting up and storing a propane tank, ranging from $300 to $1,500, but liquid propane offers cleaner burning and has an indefinite shelf life.
Diesel
Diesel generators cost around $3,000 to $20,000 for standby units. These large units are known for high efficiency and longevity but require manual refilling and sometimes have high fuel costs.
Gasoline
Gasoline generators are the most cost-effective option, at approximately $500 to $3,000. They are mostly small and portable options, and gas is readily available in most regions. However, high gas prices and shorter shelf life can make them less economical.
Solar
Solar generators cost around $2,000 to $25,000 for most homes. Most whole-home units cost $10,000 or more and involve installing solar panels. Portable solar generators are compact units with a built-in solar panel array, inverter, and battery to store generated power. They range from $1,500 to $5,000.
Small units can’t store large amounts of energy. Modern solar technology allows most units to produce power even during overcast days, although efficiency depends on the quality of solar equipment and your specific climate.
Battery Backup
A battery backup costs around $10,000 to $25,000 for whole-home units. Smaller backup batteries for critical systems cost as little as $2,000. Installation ranges from $800 to $1,500. Fuel costs depend on whether you’re pulling from the grid or a solar array, but it’s generally an economical and sustainable backup option.
Costs depend on the quality of the battery and other features. For example, some backup batteries automatically prioritize charging during off-peak grid rates to save costs.
Does Installing a Whole-House Generator Increase Home Value?
A whole-house generator can increase the value of your home, particularly if you live in a region prone to power outages, severe weather, or other power grid disruptions. Generators enhance the appeal of your home by adding convenience, comfort, and security, especially for families with medical needs that depend on electricity.
Budgeting for a Whole-House Generator
Get the most from your investment and streamline your costs with these budgeting tips for whole-house generators:
Get several estimates and compare costs for equipment and installation.
Choose the right size generator to avoid overspending on an overpowered unit.
Look for installation discounts, such as for off-season or special promotions.
Opt for a fuel-efficient generator with features that help you optimize consumption and save on fuel costs.
How HomeAdvisor Gets Its Cost Data
No place is more important than your home, which is why HomeAdvisor connects homeowners with local pros to transform their houses into homes they love. To help homeowners prepare for their next project, HomeAdvisor provides readers with accurate cost data and follows strict editorial guidelines. We surveyed thousands of real customers about their project costs to develop the pricing data you see, so you can make the best decisions for you and your home. We pair this data with research from reputable sources, including the U.S. Bureau of Labor Statistics, academic journals, market studies, and interviews with industry experts—all to ensure our prices reflect real-world projects.
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FAQs
How do I maintain a generator?
Perform generator maintenance at least annually. Refer to your owner’s manual for instructions for oil changes, air filter replacement, spark plug replacements, cleaning, and battery testing. Avoid leaving gasoline in your tank if you don’t plan to use it for an extended period. Run or exercise your generator periodically to keep its parts well-lubricated. If you notice problems with your generator, schedule a repair to avoid escalating damage.
How long does a generator last?
With regular maintenance, a generator can last up to 50 years, and most standby generators last up to 3,000 hours. Avoid running your unit for more than 500 continuous hours, and look for extended warranties to maximize your investment.
How large of a generator do I need?
The size of your generator depends on the size of your home and its power consumption. You'll need more for a home with central AC, electric heat, and electric appliances. Most mid-size homes in the U.S. need a generator that produces between 22kW and 32kW of power for reliable whole-home backup. You'll only need about half that for critical circuits.
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