How much does a generator cost?
Ashburn, VA

How much does a generator cost?

Ashburn, VA

How much does a generator cost?

$500 – $2,500portable generator cost (unit only)
$900 – $3,800portable generator cost (connected to house)
$6,000 – $11,000whole house generator cost installed

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

$500 – $2,500 portable generator cost (unit only)

$900 – $3,800 portable generator cost (connected to house)

$6,000 – $11,000 whole house generator cost installed

Get free estimates for your project or view our cost guide below:
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Kristen Cramer
Written by
Kristen Cramer
Fact-checked by
Tom Grupa

Average generator cost

A portable generator costs $500 to $2,500 for the unit or $900 to $4,000 total when connecting to a house. Portable units power up to multiple appliances plus 10+ lights. A whole house generator costs $3,000 to $6,000 for the unit or $6,000 to $11,000 installed.

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.

Get free estimates from home generator installers near you.

Generator installation costs

Total installation costs depend on the generator's size (kW), whether it's standby vs. portable, fuel source, accessories, and the wiring and hook up complexity.

Generator installation cost
Factor Portable generator Whole house generator
Generator unit $500 – $2,500 $3,000 – $6,000
Installation cost to hook to house $400 – $1,500 $3,000 – $5,000
Total cost installed $900 – $4,000 $6,000 – $11,000

  • A portable generator installation includes installing a manual transfer switch and optionally running it to a gas line. Alternatively, heavy-duty extensions cords rated for 30 to 50 amps cost $30 to $200 for plugging in appliances directly.

  • A whole house generator installer pulls permits, sizes the system, pours a concrete pad, installs the electrical wiring, install an automatic transfer switch, installs the propane or gas plumbing, installs accessories, and connects it to the utility grid.

Cost breakdown to install a generator

  • A transfer switch connects a generator to a home's electrical panel. Transfer switch installation costs $400 to $2,500 on average.

  • Gas line installation costs $12 to $25 per linear foot and is required for natural gas and propane generators.

  • Propane tanks cost $400 to $1,800 on average and are required for propane generators.

  • Generator permits cost $80 to $450 on average.

  • A concrete pad costs $150 to $400 for a permanent generator.

  • A wheel kit costs $30 to $300 and makes it easier to move a heavy generator.

  • A portable generator cover costs $20 to $165.

Portable generator cost vs. standby

Portable generators are smaller and cheaper than backup generators, but are less powerful, must be started and refueled manually, and shouldn’t run for more than two consecutive days.

Standby backup generators are permanently installed outside the home, start automatically when the power goes out, and can power the entire house for up to 3 weeks straight.

Portable vs. standby generator cost
Portable vs. standby generator cost
Portable generator cost vs. standby
Factor Portable Standby
Cost (unit only) $500 – $2,500 $2,000 – $6,000
Lifespan 2,000 – 5,000 hours 10,000 – 30,000 hours
Power Output 2 – 10 kW 7 – 22 kW
Fuel Cost $10 – $70 per day $30 – $170 per day
Fuel Needs 12 – 20 gallons of gasoline or diesel per day 20 – 75 gallons of liquid propane or 3,000 to 8,000 cubic feet of natural gas daily
  • Smaller and less expensive
  • Lower installation costs
  • Can power lights and essential appliances
  • Prevents food from spoiling during an outage
  • Easy to move around
  • Require minimal maintenance
  • Useful for camping, outdoor events, or construction site
  • Can power a whole house
  • Quieter than a portable generator
  • Can run for days or weeks continuously
  • Starts automatically
  • Can power sensitive electronics
  • Can power heating, air conditioning, and hot water heater
  • Noisy
  • Significantly less powerful
  • Require manual start and refueling
  • Produces hazardous fumes
  • Requires space for storage
  • Can’t power sensitive electronics
  • Can’t power heating or air conditioning
  • Can’t run for more than two consecutive days
  • More expensive
  • Requires professional installation
  • Permanently fixed in place
  • Requires regular maintenance
  • Requires propane or diesel fuel delivery or access to a natural gas pipeline

Generator prices by fuel type

Portable gasoline generators cost $500 to $2,500 for a 3 to 10 kW backup unit. Whole house generators cost $2,000 to $6,000 a natural gas or liquid propane system, without installation. Standby backup diesel generators cost $5,000 to $18,000.

Generator costs by fuel type
Fuel Type Portable Whole house / standby
Gasoline $250 – $4,500 --
Natural Gas $900 – $4,300 $2,000 – $6,000
Liquid Propane $250 – $4,000 $2,000 – $6,000
Diesel $3,300 – $6,700 $5,000 – $18,000
Solar $500 – $3,300 --

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

Gasoline generator cost

Portable gasoline generators cost $500 to $2,500 for a 3 to 10 kW unit. Gasoline generators have lower upfront costs and can power essential appliances during brief outages. However, they are noisy and require storage space for the generator and gas, which has a shorter shelf-life than other fuels.

Gasoline powered portable generator at home
Gasoline powered portable generator at home

Natural gas generator cost

Natural gas generators cost $2,000 to $6,000 for a whole house unit, depending on size. They can be installed to a home’s existing gas line and require no fuel storage. Natural gas is cheaper than diesel or propane, but relies on pipelines that may be shut off or damaged during severe storms.

20 kW whole house generator with natural gas installation
20 kW whole house generator with natural gas installation

Liquid propane generator cost

Liquid propane generators cost $250 to $4,000 for portable models or $2,000 to $6,000 for permanent backup units, depending on size. Liquid propane lasts longer and burns cleaner than other fuels but is more expensive and requires a large storage tank, which increases installation costs.

Diesel generator cost

Portable diesel generators cost $3,300 to $6,700 and whole-house diesel generators cost $5,000 to $18,000. Diesel generators are more efficient, reliable, and require less upkeep than natural gas or propane generators. However, they cost more, require manual refueling, and emit pollutants.

Solar generator cost

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Portable solar generators cost $500 to $3,300 and are ideal for apartment and condo residents or homeowners seeking an environmentally friendly solution. Solar generators run quietly, produce no fumes, and can be used indoors, but can’t store enough energy to power a whole home.

Generator rental cost

Renting a small portable generator costs $40 to $110 per day without fuel, depending on the power capacity and local rental rates. Renting an industrial towable generator costs $300 to $1,000 per week, depending on the size.

Cost To Rent Portable Generator
Power Capacity Rental Price Per Day
1 – 2.5 kW $40 – $55
3 – 4 kW $50 – $65
5 – 7 kW $70 – $90
8 – 10 kW $80 – $110
100 – 300 kW Towable $300 – $500 per week
500+ kW Towable $700 – $1,100 per week

Generator FAQs

Can portable generators run a house?

Portable generators connect to a home's electrical panel with a transfer switch or interlock kit. This allows the generator to power lights and essential appliances for outages lasting less than two days. However, portable generators can’t power heating and cooling systems or sensitive electronics.

How much does it cost to run a generator?

A small 7 kW portable generator costs $10 to $70 per day to run, while a larger 15 to 20 kW whole-home generator costs $30 to $170 per day to run all day. Costs depend on the generator’s size, fuel type, and local gasoline, propane, diesel, or natural gas prices.

Generator cost to run per day - chart
Generator cost to run per day - chart
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 generator run continuously?

Most portable generators run for 8 to 14 hours with a ½ power load and one tank of fuel. Portable generators should not run for more than 24 hours continuously without a break. Manufacturers recommend running a standby generator for up to 500 hours continuously, or about three weeks.

Time A Generator Can Run
Type Continuous Hours
Portable 8 – 14
Standby Up to 500

How much fuel does a generator need?

A standard 5-kilowatt portable generator consumes 0.75 gallons per hour or 18 gallons per day, which costs about $40 per day. 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.

Generator Fuel Consumption
Fuel Type Generator Size
5 – 7 kW 15 kW 20 kW
Gasoline 0.75 GPH -- --
Liquid Propane 1.42 GPH 3.16 GPH 3.45 GPH
Natural Gas 118 CfH 133 CfH 330 CfH
Diesel 0.60 GPH 1.22 GPH 1.60 GPH

*Gallons Per Hour (GPH) , Cubic Feet Per Hour (CfH)

How long does a generator last?

Portable generators last up to 10 years and provide 2,000 to 5,000 hours of power. A standby generator lasts 15 to 30 years and provides 10,000 to 30,000 hours of use with proper maintenance.

Generator lifespan by type
Type Lifespan In Years Hours of Runtime
Portable Up to 10 2,000 – 5,000
Standby 15 – 30 10,000 – 30,000

What size generator do I need?

Use the watt usage chart for generators below to calculate the size required for a house. In general:

Get free estimates from home generator installers near you.
  • Large 20 kW standby generators power a whole house.

  • Mid-range 10 to 16 kW generators power major appliances, including central air conditioning, or an entire home if paired with a smart load manager.

  • Portable 5 to 10 kW generators power multiple appliances and ten lights.

  • A 4 kW generator powers an RV.

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.

Getting estimates from generator installers

Home generator installation involves complex electrical work and gas plumbing that requires hiring a electrical company near you for safety.

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

  • Look for licensed electricians with experience installing generators.

  • For natural gas and propane generators, select a certified for gas plumber.

  • 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.

  • Ask for a written contract and warranty.

  • Get a full breakdown of all costs involved.

  • Avoid making large payments upfront.