How Much Does It Cost to Install a Generator in 2026?
The average cost to install a whole house generator is $5,000 to $15,000. Here is what drives that range, portable vs standby generators, and what size you actually need.
Power outages are becoming more frequent and more prolonged across the country. A whole house standby generator turns on automatically within seconds of an outage and runs on natural gas or propane, making it completely hands-free. The average cost to install one runs $5,000 to $15,000 all in.
Average Cost to Install a Generator in 2026
| Generator Type | Unit Cost | Installed Total |
|---|---|---|
| Portable generator (3,000 to 8,000 watts) | $400 to $1,500 | $400 to $1,500 |
| Portable with transfer switch | $400 to $1,500 | $800 to $2,500 |
| Standby generator (10kW) | $2,000 to $3,500 | $5,000 to $8,000 |
| Standby generator (20kW) | $3,500 to $5,500 | $7,000 to $12,000 |
| Standby generator (22kW+) | $5,000 to $9,000 | $10,000 to $18,000 |
Portable vs Standby: Which Do You Need?
Portable generators are the affordable option for occasional short outages. A quality portable generator powers essential appliances including a refrigerator, window AC unit, phone chargers, and lights during an outage. Look for at least 3,500 watts of running power with a reliable engine and low-oil shutoff protection. Never run a portable generator indoors or in a garage due to carbon monoxide risk.
Standby generators install permanently outside your home, connect to your natural gas or propane supply, and start automatically within 10 to 30 seconds of a power outage. They run indefinitely as long as fuel is supplied. They are the right choice for anyone who works from home, has medical equipment, or simply wants complete peace of mind during outages.
What Size Generator Do You Need?
A 10kW standby powers essential circuits but not central AC. A 16kW powers most of the home including a smaller central AC. A 20kW powers the entire home. An HVAC contractor or generator installer can calculate your exact needs based on your home's electrical load.
What Drives the Cost Up
Natural gas line extension adds $300 to $1,000 if the gas line needs to be run to the generator location. Propane tank installation for homes without natural gas adds $1,500 to $3,500. Permitting is required in most municipalities and adds $100 to $400.
Annual Maintenance
Standby generators require annual service including oil change, spark plug replacement, and load testing. Annual maintenance runs $150 to $300 and is critical for reliable operation when you actually need it.
Bottom Line
Budget $7,000 to $12,000 for a 16 to 20kW standby generator professionally installed on natural gas. For occasional outages on a budget, a quality portable generator at $600 to $1,000 is a reasonable alternative. Either way, never run any generator indoors.
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