How much does a whole house generator cost?
Ashburn, VA

How much does a whole house generator cost?

Ashburn, VA

How much does a whole house generator cost?

$3,000 – $5,000average cost to install (labor only)
$6,000 – $11,000average total cost installed (unit & labor)

Get free estimates for your project or view our cost guide below:

$3,000 – $5,000 average cost to install (labor only)

$6,000 – $11,000 average total cost installed (unit & labor)

Get free estimates for your project or view our cost guide below:
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Kristen Cramer
Written by
Kristen Cramer
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Whole house generator cost

A whole house generator costs $6,000 to $11,000 installed on average. Home generators cost $3,000 to $6,000 alone on average. The labor cost to install a whole house generator is $3,000 to $5,000 on average or $5,000 to $12,000+ for longer distances or > 20 kW systems.

In comparison, portable generators cost $500 to $2,500, plus $400 to $1,300 for a transfer switch.

Whole house generator cost - chart
Whole house generator cost - chart
Whole house generator cost
Item Average cost Long distances or > 20 kW
Whole house generator $3,000 – $6,000 $4,500 – $12,000+
Installation $3,000 – $5,000 $5,000 – $12,000+
Total cost installed $6,000 – $11,000 $9,500 – $24,000

  • Whole-house standby generators are permanently wired into the electric panel and automatically turn on during a power outage.

  • Whole-home generators cost $30 to $170 per day to run and provide a power source for up to 500 hours continuously or three weeks.

  • Standby generators last 15 to 30 years or 10,000 to 30,000 hours.

Get free estimates from home generator installers near you.

Home generator costs by size

Standby generators can power select circuits or a whole home, depending on the generator's size in kilowatts (kW) and circuits in the transfer switch.

Generator cost by size - chart
Generator cost by size - chart
Generator cost by size
Size Unit price range Typical coverage
2 – 5 kW $250 – $1,400 Portable: One appliance and a few lights.
7 – 10 kW $2,000 – $3,000 Portable: 10 lights, refrigerator, sump pump, well pump, microwave, TV, laptop, coffee maker, and furnace fan.
13 – 16 kW $3,000 – $4,500 Full home under 1,500 square feet.
17 – 20 kW $4,000 – $6,000 Full 1,500 to 3,000 square foot home.
22 – 25 kW $4,500 – $12,000 Full 3,000 to 5,000 square foot home.
30 – 48 kW $10,000 – $16,000 Large luxury home or commercial applications.

*Not including installation. Prices depend on the size, type, fuel source, brand, and accessories.

Whole house generator costs installed by type

Whole home natural gas or liquid propane generators cost $2,000 to $6,000 without installation. Whole house diesel generators cost $5,000 to $18,000.

Whole house generator costs by fuel type
Fuel Type Unit price range Details
Natural Gas $2,000 – $6,000 Installs to a home’s existing gas line and require no fuel storage.
Liquid Propane $2,000 – $6,000 Lasts longer and burns cleaner than other fuels but is more expensive and requires a large storage tank.
Diesel $5,000 – $18,000 More efficient, reliable, and require less upkeep. But, they cost more and require manual refueling.

*Prices for units with power capacity of 2 to 24 kW. Not including installation.

Cost factors of whole house standby generator

Standby generator installation costs depend on the size, fuel source, distance from the electrical panel and gas meter, and amount of wiring and gas plumbing to hook up.

Complex jobs may require long trenches for electrical conduit and gas pipes, propane tank installation, or higher labor costs to install liquid-cooled generators.

Standby generator installation cost factors
Factor Average cost
Home Energy Assessment Free With Installation
Labor Charges For Electrician $40 – $100 per hour
Automatic Transfer Switch Installation $600 – $2,500
Electrical Wiring $6 – $8 per foot
Gas Line Installation $12 – $25 per foot
Concrete Pad $150 – $400
Propane Tank Installation $400 – $1,800
Permits $80 – $450

  • Electricians charge $50 to $130 per hour to install wiring and hook up a backup generator to the electrical panel.

  • Natural gas and liquid propane generators require gas plumbing. Gas line installation costs $12 to $25 per linear foot.

  • A liquid propane generator requires a fuel tank. Propane tanks cost $400 to $1,800 on average.

  • Separate electrical, plumbing, and mechanical permits may be required. Permits cost $80 to $450 total on average.

  • A 3" to 4" thick pre-cast concrete pad costs $150 to $400 for a generator.

  • DIY generator maintenance kits cost $20 to $110. Annual generator maintenance contracts cost $200 to $650 per year and include a full inspection and oil and filter changes.

Standby generator installed in home backyard
Standby generator installed in home backyard

Generator transfer switch or interlock installation

A transfer switch or interlock connects a generator to a home's electrical panel.

  • The average cost to install a generator transfer switch is $400 to $2,500 total.

  • A generator interlock costs $400 to $850 installed and allows a portable generator to connect to the electrical panel without a transfer switch.

Home generator accessories & prices

Whole house generators may need additional accessories depending on the location and system type:

Get free estimates from home generator installers near you.
Home generator accessories & prices
Accessory Price Description
Generator Battery $70 – $300 Starts the generator when the electricity goes out.
Cold-Weather Kit $130 – $500 Ensures the generator starts in regions where temperatures drop below freezing.
Wireless Monitor $200 – $210 Provides access to generator status from inside the home.
Smart Load Manager $130 – $250 Allows smaller generators to power more appliances by balancing the electric load.
Fascia Kit $65 – $130 Protects the generator’s base from rodents and insects.

Generac generator costs vs. other brands

Generac generators cost $2,000 to $5,000 for a 7 to 24 kW whole-house unit, plus $3,000 to $5,000 for installation. Generac’s standby generators turn on automatically during power outages and run on natural gas or liquid propane. Generac is the leading brand in whole-home generators.

Generac generator costs - chart
Generac generator costs - chart
Generac Generator Prices
Power Capacity Average Price
7 kW $2,000
10 kW $3,000
16 kW $3,800
17 kW $4,000
20 kW $4,500
22 kW $5,000
30+ kW $12,000

*Prices not including installation.

Other standby generator brands to compare are Kohler, Briggs & Stratton, Honda, and Cummins.

Kohler Generator Cost

A Kohler home generator costs $2,700 to $16,000 depending on size, ranging from 6 to 48 kW. Kohler generators run on natural gas or liquid propane, feature remote smartphone monitoring, and include an automatic transfer switch to turn on automatically during power outages.

Briggs & Stratton Generator Cost

Briggs & Stratton home generators cost $2,400 to $15,300 depending on size, with models ranging from 10 to 48 kW. Briggs & Stratton generators feature wireless monitoring, automatic low oil shutdown, and power management to control power distribution to select appliances and prevent overloads.

Cummins Generator Cost

Cummins standby generators cost $3,100 to $13,900 for models ranging from 13 to 40 kW. Cummins generators feature sound-insulated enclosures, remote diagnostics, and intelligent load management to balance power use across multiple appliances so a smaller generator can power an entire home.

Home backup generator FAQs

Does a whole house generator add value to your home?

A whole house generator provides up to a 150% return on investment and can increase the overall value of your home by 5% according to Consumer Reports and Remodeling magazine.

What size generator for a whole house?

Powering a whole house up to 3,000 SF typically requires a 13 to 20 kW generator. Use the watt usage chart for generators below to calculate the size required for a house.

Generator size calculator for house
Type of Load Wattage Generator Size
7 kW 20 kW 48 kW
Two Lighting Circuits 200 W    
Four Lighting Circuits 400 W    
10 Lighting Circuits 1000 W    
Refrigerator / Freezer 1200 W
Sump Pump 1000 W
Well Pump 1000 W
Furnace Fan 500 W
Garage Door Opener 850 W
Microwave Oven 1000 W
Electric Oven 2000 W  
Radio 150 W
Television 300 W  
Laptop 50 W  
Desktop Computer 200 W  
4-Ton Central Air Conditioner 8500 W  
Washing Machine 1200 W  
Electric Clothes Dryer 3000 W    
Coffee Maker 900 W  
Gaming Console 100 W    
Jacuzzi Bathtub 1500 W    
Hot Tub 6000 W    
EV Charging Station 7200 W    

*Running wattage is shown. Some appliances startup wattage can be double the running wattage.

How much does a whole house generator cost to run?

A whole-home generator costs $30 to $170 per day to run all day depending on the size and fuel source. Whole-house 15 to 20 kW standby generators consume 133 to 330 cubic feet of natural gas or 3.16 to 3.45 gallons of liquid propane per hour.

Cost to run a generator per day
Fuel source Generator size
7 kW 15 kW 20 kW
Natural Gas $10 – $20 $22 – $32 $30 – $40
Liquid Propane $60 – $70 $145 – $165 $150 – $170
Diesel $32 – $40 $90 – $110 $100 – $120
Gasoline $55 – $70 -- --

*Costs depend on current and local fuel prices.

How long can a whole house generator run continuously?

Manufacturers recommend running a whole house generator for up to 500 hours continuously, or about three weeks.

How long does a whole house generator last?

A whole house generator lasts 15 to 30 years and provides 10,000 to 30,000 hours of use with proper maintenance. Reputable brands offer 5- to 10-year limited warranties on whole house generators.

Who installs whole house generators?

Generator installers and most electricians install whole house generators. Installation can also be handled by general contractors.

Get free estimates from home generator installers near you.

Where should a whole house generator be installed?

  • For safety, a generator should be located outside at least five feet away from doors, windows, vents, and flammable material.

  • Most generators produce 60 to 70 decibels (dB) from 25 feet away, similar to a central air conditioner. Some city properties are tighter, increasing the noise level, which may be regulated by local noise ordinances.

Getting estimates from whole house generator installers

A home generator installer pulls permits, determines the power and size generator needed to run the house, pours a concrete pad, installs the wiring and plumbing, and safely connects it to the utility grid. Follow these steps to find the best pro for the job:

  • Get at least three in-person estimates to compare.

  • Look for electricians with experience installing home generators.

  • For natural gas and propane generators, select a pro who is certified for gas plumbing.

  • Read reviews and check out their previous work on HomeGuide and Google.

  • Select companies that are insured, bonded, and have been in business for longer than five years.

  • Avoid selecting the lowest quote as quality may suffer.

  • Ask for a written contract and warranty.

  • Get a full breakdown of all costs involved.

  • Avoid making large payments upfront. Come up with a payment schedule for the work completed.

Questions to ask installers

  • How long have you been installing generators?

  • How many generators have you installed?

  • Will your company handle the gas plumbing, or do you use subcontractors?

  • Can you provide references of past work?

  • Are you licensed, bonded, and insured?

  • What costs might be associated with the installation?

  • What permits do I need, and will you obtain them?

  • What is your payment schedule?