Whole-house generator cost by size
| Generator size | Installed price | Good to know |
|---|---|---|
| Small, 7.5 to 10 kW (essentials only) | $3,500–$8,500 | Runs a few essentials |
| Medium, 14 to 18 kW (critical systems) | $5,500–$10,500 | Covers critical systems in an average home |
| Large, 20 to 24 kW (most of the house) | $6,500–$11,500 | Most of a larger home |
| Extra large, 26 to 32 kW (large homes) | $8,000–$20,000 | The range widens fast above this size |
The guides we read quote generators in three different ways: the unit alone by size, installation labor alone, and a total installed figure. We combined the sourced unit range for each size with the sourced labor range, so each price here covers the unit and a basic installation, with the labor share adjusted for your state. Treat it as a planning range and get quotes.
What changes the price
Size is the biggest factor, but installation matters as much. A longer run for the gas line or electrical, a hard-to-reach location, and a main panel that cannot take the load all raise the bill. Fuel type changes the work too: natural gas needs a connection to the utility line, while propane needs a tank. The guides give gas line work per foot, or not at all, so we do not price it. Ask for it as its own line.
Extra costs to expect
| Item | Typical cost | When it applies |
|---|---|---|
| Transfer switch | $600–$2,500 | If your quote prices it separately from labor |
| Concrete or gravel pad | $150–$1,000 | If the quote does not include a pad |
| Electrical subpanel | $500–$2,000 | When the main panel cannot take the load |
| Dedicated circuit | $500–$1,000 | If a new circuit is needed |
| Permit | $50–$450 | Electrical and fuel line work usually need their own permits |
The calculator leaves these extras unticked because some installers fold them into the labor price. Tick only the ones your quote lists as separate lines, so nothing is counted twice.
Questions to ask before you hire
- Is the price for the unit, installation, transfer switch and permits together?
- How was the generator sized for my home's loads?
- Who handles the gas line or propane tank, and is it included?
- Do you need to upgrade my panel or add a subpanel?
- What is the warranty, and who services the unit?
Methodology and sources
We combine each size's sourced unit price with the sourced installation labor range, adjust the labor share for your state's electrician wages, and price the transfer switch, pad, electrical work and permit separately. Read how we estimate costs.
- HomeAdvisor: install a generator — unit prices by size, labor, transfer switch, pad, permits
- Bob Vila: whole-house generator cost — unit prices by size, labor, subpanel, circuit
- HomeGuide: whole-house generator cost — unit prices, labor, transfer switch, pad, permits
- BLS OEWS May 2025, State (SOC 47-2111, Electricians) — state labor index, an electrician proxy
What each source reports
Our estimate does not rely on any single page. This table lists each page we used and the figures it reports, so you can see where the ranges come from.
| Source | What it reports |
|---|---|
| HomeAdvisor |
|
| Bob Vila |
|
| HomeGuide |
|
Common questions about generator installation costs
How much does generator installation cost?
A typical job (14 to 18 kw generator) comes to about $8,150 nationally, within a range of $5,550 to $10,950. Use the calculator above to adjust for your state, the options you choose and any extras.
How much does a standby or whole house generator installation cost?
A 14 to 18 kW generator for critical systems comes to about $5,550–$10,950 installed, and a 20 to 24 kW generator, which covers most of a house, to about $6,550–$11,950. A 26 to 32 kW unit for a large home comes to about $8,050–$20,450.
Where do these prices come from?
They come from 3 published cost pages from 3 publishers, last checked Oct 8, 2026. We report what those pages say and do not invent figures; the table above shows each source.
How does my state change the estimate?
The labor part of the price is scaled by the average wage for the relevant trade in your state, using Bureau of Labor Statistics data. Materials and equipment are not adjusted.
Why might a contractor's quote differ from this estimate?
A quote reflects your specific scope, access, local demand and what the contractor includes. Ask for line items rather than a single total so you can compare bids on the same basis.
All 3 sources behind these prices
Every figure in the calculator comes from one or more of these pages, with the number each one supports in the link text.
- HomeAdvisor: a 7.5-10 kW unit $2,000 to $3,500, and installation labor $1,500 to $5,000 (updated Jun 2026)
- Bob Vila: a 7.5-10 kW unit $2,000 to $3,500, and installation $1,500 to $5,000 (updated Jun 2024)
- HomeGuide: a 7-10 kW unit $2,000 to $3,000, and labor averaging $3,000 to $5,000 (written Dec 2025, no update date)