Generator installation cost in the United States ranges from $1,500 to $20,000 depending on generator type and size. A portable generator costs $500-$2,000, while a whole-house standby generator costs $8,000-$20,000 installed. Use our free calculator below to get an instant estimate for your project.
Generator Installation Cost by Type
| Generator Type | Unit Cost | Installation Cost | Total Cost |
| Portable | $500–$1,500 | $0–$200 | $500–$1,700 |
| Standby 7–10 kW | $2,000–$4,000 | $500–$1,500 | $2,500–$5,500 |
| Standby 14–20 kW | $4,000–$8,000 | $1,000–$2,500 | $5,000–$10,500 |
| Whole house 22–38 kW | $8,000–$15,000 | $2,000–$5,000 | $10,000–$20,000 |
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What Factors Affect Generator Installation Costs?
1. Generator Type and Size
Portable generators are affordable but require manual setup and can’t power your whole home. Standby generators turn on automatically within seconds of a power outage and run on natural gas or propane. A 7-10 kW standby generator powers essential appliances. A 20+ kW unit powers your entire home including HVAC.
2. Fuel Type
Natural gas generators connect to your existing gas line at low installation cost. Propane generators require a tank — a 500-gallon tank costs $800-$1,500 installed. Diesel generators are common for commercial use but less popular for residential due to fuel storage requirements. Natural gas is the most convenient fuel for standby generators.
3. Transfer Switch
A transfer switch safely disconnects your home from the grid when the generator runs — this is required by code and protects utility workers. A manual transfer switch costs $400-$800 installed. An automatic transfer switch (ATS) costs $1,000-$3,000 but switches power automatically without any action from you.
4. Electrical Panel Upgrades
If your electrical panel is outdated or at capacity, you may need an upgrade before generator installation. A panel upgrade costs $1,500-$3,000 and adds to total project cost. Always have an electrician assess your panel before purchasing a generator.
5. Permits
Generator installation requires electrical and gas permits in most US states costing $100-$500. Your installer should handle permit applications. Unpermitted generator installations can void your homeowner’s insurance and cause problems when selling your home.
How to Save Money on Generator Installation
- Choose a standby generator sized for essential circuits only — not whole-house power
- Install natural gas over propane if you have existing gas service — eliminates tank cost
- Get at least 3 quotes from licensed electricians and generator installers
- Buy during off-season (spring/summer) when demand is lower after winter storms
- Choose a manual transfer switch over automatic to save $500-$1,500
Frequently Asked Questions
How long does generator installation take?
A portable generator requires no installation. A standby generator installation takes 1-2 days for the unit itself plus 1-3 weeks for permits and utility approval. Whole-house generator installations with new gas lines and panel upgrades can take 2-4 weeks total.
How long do standby generators last?
A well-maintained standby generator lasts 20-30 years or 10,000-30,000 hours of operation. Annual maintenance including oil changes, filter replacement, and load testing costs $150-$300 per year. Most manufacturers offer 5-year warranties on residential standby generators.
What size generator do I need for my house?
A 7-10 kW generator powers essential circuits — lights, refrigerator, some outlets, and a window AC unit. A 14-20 kW generator powers most of your home excluding central HVAC. A 22+ kW generator powers your entire home including central air conditioning. Calculate your total wattage needs by adding up your essential appliances before choosing a size.
Bottom Line: Generator Installation Cost
Generator installation costs between $1,500 and $20,000 depending on type and size. A 14-20 kW standby generator is the most popular choice for whole-home backup power at $5,000-$10,500 installed. Use our free calculator above for a personalized estimate and always hire licensed electricians for installation to ensure safety and code compliance.