A whole-house generator costs $6,000 to $11,000 installed, unit and labor included.2 Angi’s installation average is $5,156; Fixr’s national average is $15,000 for an 18 kW system.13 Portable backups run $500 to $2,500 for the unit alone.2 Prices below are national averages* for 2026.
*National averages, not local quotes. Your price depends on generator size, fuel type, distance to the panel and gas meter, and permits. Standby generator installation is licensed-pro work.
$5,156
average install, Angi
$6,000 – $11,000
total installed, HomeGuide
$15,000
national average, Fixr
$50 – $130
electrician hourly, HomeGuide
Quick math: HomeGuide’s unit ($3,000 to $6,000) plus labor ($3,000 to $5,000) reproduces its $6,000 to $11,000 installed band exactly, our arithmetic.2 Why is Fixr’s $15,000 average so much higher? Its example job is an 18 kW system powering a 2,000 sq. ft. home with heating, cooling, and all appliances — bigger than the typical 10 to 16 kW install in Angi’s dataset.13 For essential-circuit coverage, plan on $5,000 to $8,000; for true whole-home coverage, $10,000 to $20,000.
Cost by generator size
| Size | Unit price | What it covers | Source |
|---|---|---|---|
| 2 – 5 kW | $250 – $1,400 | Portable: one appliance, a few lights | HomeGuide |
| 7 – 10 kW | $2,000 – $3,500 | Essentials: fridge, sump pump, furnace fan, lights | Both |
| 13 – 16 kW | $3,000 – $4,500 | Full home under 1,500 sq. ft. | HomeGuide |
| 17 – 20 kW | $4,000 – $6,000 | Full 1,500 to 3,000 sq. ft. home | HomeGuide |
| 22 – 25 kW | $4,500 – $12,000 | Full 3,000 to 5,000 sq. ft. home | HomeGuide |
| 26 – 32 kW | $6,500 – $15,000 | All systems incl. larger HVAC | Angi |
| 45 – 48 kW | $16,200 – $21,000 | Commercial-grade, multiple ACs | Angi |
Angi’s type tiers tell the same story differently: portable units $500 to $2,000, partial (9 to 20 kW) $2,000 to $6,300, and whole-house standby units $5,000 to $18,000 for the generator alone.1 Unit prices exclude installation.
Cost by fuel type
| Fuel | Unit price (HomeGuide) | Running cost (Angi) |
|---|---|---|
| Natural gas | $3,000 – $6,000 | $1 – $3 per hour |
| Liquid propane | $2,000 – $6,000 | ~$10 per hour |
| Diesel | $5,000 – $18,000 | $5 – $7 per hour |
Fuel choice is where operating cost diverges: a 24-hour outage costs roughly $24 to $72 on natural gas versus about $240 on propane, our arithmetic from Angi’s hourly figures.1 Natural gas needs a utility line; propane needs a storage tank at $400 to $1,800 (HomeGuide).2 HomeGuide estimates $30 to $170 per day to run a standby unit, up to 500 hours continuously.2
Installation cost factors
| Component | Cost |
|---|---|
| Automatic transfer switch | $600 – $2,500 |
| Electrical wiring | $6 – $8 per foot |
| Gas line | $12 – $25 per foot |
| Concrete pad | $150 – $400 |
| Propane tank | $400 – $1,800 |
| Permits | $80 – $450 |
| Annual maintenance | $200 – $650 per year |
All figures from HomeGuide.2 Distance is the multiplier: long trenches for conduit and gas pipe push installation from $3,000 to $5,000 up to $5,000 to $12,000+ on large or far-from-panel jobs.2 Angi adds subpanel upgrades and transfer switch work as common budget items beyond its $5,156 average.1
Standby vs. portable
A portable generator ($500 to $2,500, HomeGuide) plus a manual transfer switch ($400 to $1,300) is the budget path: roughly $900 to $3,800, our arithmetic, with no permanent install.2 Fixr’s low-end is $900 for a 5 kW portable.3 A standby unit costs more but starts itself within seconds of an outage, runs on natural gas or propane without refueling, and lasts 15 to 30 years (HomeGuide).2
Worked examples
Example 1 — essentials-only standby, 10 kW natural gas. Unit $2,000 to $3,500 (Angi) + transfer switch ($600 to $2,500) + pad ($150 to $400) + permits ($80 to $450) + labor, landing in HomeGuide’s $6,000 to $11,000 band.12
Example 2 — Fixr’s average job. 18 kW powering a 2,000 sq. ft. home fully: $15,000 national average, range $10,000 to $20,000.3 The same coverage in Angi’s 14-to-18 kW tier is $4,000 to $5,500 for the unit, our comparison — the rest is installation, switch, pad, and gas work.1
Example 3 — week-long outage operating cost. 7 days × $30 to $170 per day = $210 to $1,190 in fuel, our arithmetic from HomeGuide’s running-cost band — natural gas at the low end, propane at the high.12
FAQ
What size generator do I need? 7 to 10 kW covers essentials (fridge, sump pump, furnace fan); 17 to 20 kW covers a full 1,500 to 3,000 sq. ft. home; 22 kW+ for larger homes (HomeGuide).2
Natural gas or propane? Natural gas if you have a utility line — $1 to $3 per hour to run versus about $10 on propane (Angi). Propane works anywhere but needs a $400 to $1,800 tank (HomeGuide).12
Why do the averages disagree ($5,156 vs $15,000)? Angi’s dataset blends partial and whole-home installs; Fixr’s average assumes full-home coverage with all appliances. Match the generator to the coverage you actually want.13
Is a portable generator enough? For a fridge, some lights, and a sump pump, yes — $900 to $3,800 with a transfer switch, our arithmetic from HomeGuide’s figures. It will not start itself or run central air.2
Can I install a standby generator myself? No — it wires into your panel through a transfer switch and ties into gas plumbing, with permits required (HomeGuide).2
DIY shopping: portable generators (plain link, no affiliate relationship) — a genuine DIY purchase; standby units stay with the pros.
Sources
- Angi, How Much Does a Whole-House Generator Cost? (2026 data) and Whole-House Generator Installation: A Complete Guide (2026).
- HomeGuide, How Much Does a Whole House Generator Cost? (2026).
- Fixr, Cost to Install Whole House Generator (2022 data).
Related guides
Solar Panel Installation Cost
Electrical Panel Upgrade Cost
Electrician Cost
EV Charger Installation Cost
Sump Pump Installation Cost
All cost guides