How Much Does a Whole House Generator Cost?
Updated 28 March 2026
$5,000 to $15,000 installed for a home standby generator. Portable generators cost $500 to $2,000 but require manual setup and cannot run your whole house.
Whole House Generator Cost Estimator
Estimate your standby generator installation cost based on size, fuel type, and transfer switch choice.
Powers everything in a typical 2,000 sqft home
Best long-term option if gas line is available
Generator starts within seconds of outage
Estimated Total (18 kW installed)
$9,600
Range: $8,160 to $11,520
Generator unit
$5,500
Labor
$2,500
Transfer switch
$1,200
Permits
$400
Premium vs portable generator
$8,100 more
Standby starts automatically, powers the whole house, requires no manual setup
Quick answer
Home standby generator installed: $5,000 to $15,000. The most popular size for an average home is 16 to 22kW, which runs $7,000 to $15,000 installed. Standby generators start automatically within 10 seconds of a power outage and run on natural gas or propane indefinitely.
Cost by Generator Size
All prices include the generator unit, automatic transfer switch, concrete pad, and standard installation. Gas line work and permits are additional.
| Size | Unit + Install | Powers |
|---|---|---|
| 10kW | $5,000 to $8,000 | Lights, fridge, well pump, a few outlets. Not enough for AC. |
| 16kW | $7,000 to $10,000 | Whole house minus central AC. Most popular for average homes. |
| 22kW | $10,000 to $15,000 | Everything including one central AC unit. Recommended for most homes. |
| 48kW | $15,000 to $25,000 | Large homes, multiple AC units, home offices with high draw equipment. |
What Size Do You Need?
Standby vs Portable vs Inverter Generator
| Type | Cost | Starts Automatically | Max Power | Notes |
|---|---|---|---|---|
| Standby (permanent) | $5,000 to $15,000 | Yes (10 sec) | 10 to 48kW | Natural gas or propane. Runs indefinitely. |
| Portable (gas) | $500 to $2,000 | No | 3 to 12kW | Manual setup outside. Limited run time per tank. |
| Inverter (portable) | $800 to $3,000 | No | 1 to 7kW | Quiet, clean power for electronics. Not enough for AC. |
Fuel Type Comparison
Natural gas
Cheapest to operate. Never runs out since it connects to the utility line. Requires an existing gas line nearby. Cannot be stored -- depends on utility service.
Propane
Works anywhere regardless of utility access. Requires a 250 to 500-gallon tank ($800 to $2,000 installed). Must monitor fuel levels and schedule refills before storm season.
Diesel
Most common in commercial settings. Fuel degrades after 12 to 18 months so stored fuel must be treated or rotated. Noisier than gas units and requires separate fuel storage.
Frequently Asked Questions
How much does a whole house generator cost installed?
$5,000 to $15,000 for a home standby generator. A 10kW unit runs $5,000 to $8,000 and covers essential circuits. A 22kW unit for whole-house coverage including AC runs $10,000 to $15,000. Add $300 to $800 for gas line connection and $100 to $300 for permits.
What size whole house generator do I need?
10kW covers lights, refrigerator, and a few outlets but not AC. 16kW covers the whole house minus central air. 22kW covers everything including one central AC unit. For large homes or multiple AC zones, you need 30kW or more. A licensed electrician can calculate your exact load requirements.
What fuel type is best for a standby generator?
Natural gas is most convenient if you have a gas line -- it never runs out and costs least to operate. Propane works anywhere but requires a tank and fuel monitoring. Diesel is efficient but noisy and the fuel degrades over time. Most residential standby generators run on natural gas or propane.
How long does standby generator installation take?
One to two days of physical work once permits are approved. Permitting takes 2 to 4 weeks in most areas. The installation includes pouring a concrete pad, connecting the gas line, installing the automatic transfer switch, and wiring to your electrical panel.