How much does generator installation cost?
A portable-generator inlet with an interlock or manual transfer setup often costs $700-$2,500 installed. A standby home generator commonly costs $5,000-$12,500+ installed, and larger whole-house systems with fuel, pad, transfer switch, and panel work can run $15,000+.
The generator unit is only part of the price. Safe installation depends on the transfer method, generator size, fuel line, concrete pad, panel compatibility, permits, inspection, and whether the system powers selected circuits or the whole home.
Generator installation cost by setup
Portable generator inlet with interlock
$700-$2,500How to tellYou own or plan to buy a portable generator and want a safe way to feed selected circuits
The fixInstall exterior inlet, interlock kit, breaker, wiring, labeling, and inspection where required
Manual transfer switch
$1,200-$2,500+How to tellYou want selected circuits available during an outage without backfeeding risk
The fixInstall transfer switch, connect chosen circuits, label loads, and test with generator
Small standby generator
$5,000-$9,000How to tellYou want automatic backup for critical circuits such as fridge, heat, sump, internet, and lights
The fixGenerator, pad, automatic transfer switch, electrical connection, permit, fuel hookup
Whole-house standby generator
$9,000-$18,000+How to tellYou want automatic backup for most or all home loads during outages
The fixLarger generator, automatic transfer switch, load calculation, fuel sizing, pad, permits
Fuel, panel, or site upgrades
Add $500-$5,000+How to tellPanel needs work, gas line is undersized, generator location is far away, or code clearance is tight
The fixPanel modifications, gas/plumbing work, trenching, concrete pad, service upgrade, or load management
Before you price a generator
- List what must run during an outage: refrigerator, sump pump, furnace blower, well pump, medical equipment, internet, lights, or whole-home AC. This decides the generator size.
- Decide whether you want automatic standby backup or a portable generator connection. Portable setups cost less but require manual setup and fuel.
- Do not use a suicide cord or backfeed a dryer outlet. Backfeeding can injure utility workers and destroy equipment.
- Check fuel availability before choosing the generator. Natural gas, propane, diesel, and gasoline all change installation and operating costs.
Unlock the hiring checklist
Use this before you call an electrician, so you know what to ask and what to avoid.
Call a pro when…
- Any generator will connect to the home's electrical system
- You need a transfer switch, interlock, inlet, automatic standby generator, or panel work
- The generator will serve a well pump, sump pump, furnace, medical equipment, or other critical load
- Fuel line sizing, concrete pad placement, exhaust clearance, or local permits are involved
Repair or replace?
Use a portable generator inlet or manual transfer setup when you only need critical circuits and can manage setup during outages. Choose standby only when automatic backup matters, outages are frequent, or critical equipment cannot tolerate manual setup. A whole-house standby system is convenient but not always the best ROI if a smaller critical-load system solves the real problem.
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Related questions
What is the cheapest safe way to connect a generator to a house?
Usually a portable generator inlet with a properly installed interlock or manual transfer switch. It is much safer than extension-cord improvising or illegal backfeeding, and it costs far less than a standby generator.
Do I need a transfer switch for a generator?
Yes if the generator connects to house wiring. A transfer switch or approved interlock prevents backfeeding utility lines and keeps generator power isolated from grid power.
How big of a generator do I need?
A critical-load setup may only need enough power for refrigerator, sump, furnace blower, internet, and lights. Whole-house systems need a load calculation, especially if you want central AC, electric heat, well pumps, or large appliances during an outage.
Can an electrician install the whole generator system?
Electricians handle the panel, transfer equipment, wiring, permits, and load side. Standby generators often also need a plumber or gas contractor for fuel line work and sometimes a concrete or site-prep contractor for the pad.