A whole-house generator is a significant investment, so it helps to understand what actually goes into the price before you get a quote. According to 2026 industry cost data, a whole-house standby generator typically costs between $7,000 and $20,000 fully installed, with most homeowners paying $10,000 to $15,000 for a common 14kW to 22kW system. Smaller systems sized for essential circuits only can run closer to $7,000 to $12,000, while larger homes or complex installations can exceed $20,000.

The important thing isn’t memorizing a single average — it’s understanding what’s driving your specific price before buying anything. See How Much Does It Cost to Install a Generator? for a closer look at that side of the project specifically.

Typical Cost by System Size

Based on 2026 national cost data:

Generator Size	Typical Installed Cost
8–10 kW (essential circuits only)	$7,000 – $13,000
14 kW (common whole-home choice)	$10,000 – $16,000
20–22 kW (larger home, central AC)	$13,000 – $24,000
30 kW+ (large home, heavy loads)	$20,000 – $35,000+

These figures reflect a range across multiple 2026 industry sources (Angi, HomeGuide, and specialty generator cost guides), and include the unit, automatic transfer switch, pad, gas hookup, electrical labor, and permits — a complete installed price, not just the equipment.

What’s Actually Driving the Cost?

The generator unit itself is often less than half the total price. A rough breakdown for a typical installation: about 40 percent goes to the unit, 25 percent to the transfer switch and electrical work, 15 percent to the gas line connection, and the remainder to the concrete pad, permits, and startup. This is why a generator advertised at a low price can still turn into a much larger project once installation is factored in — ask your installer for a complete breakdown, not just the unit cost.

What Affects the Cost of a Whole-House Generator?

Several factors can combine to determine the final installed price.

• Generator size (capacity) — Sizing should be based on an actual load calculation, not a guess before buying — see What Size Generator Do I Need for My House? for how that works.
• Fuel type — Natural gas systems draw from your home’s existing gas line, which can simplify installation if that line is already accessible near the generator’s planned location. Propane systems require a dedicated tank, adding $800 to $2,500 if you don’t already have one sized appropriately.
• Electrical work — Connecting a standby generator requires an automatic transfer switch and proper integration with your home’s electrical panel.
• Gas line work — If your home’s existing gas line isn’t sized or positioned to supply the generator, running or upgrading gas lines adds both materials and labor.
• Site preparation and location — The generator needs a proper pad and adequate clearance from windows and doors per code and manufacturer requirements.
• Permits and inspections — Most jurisdictions require permits for whole-house generator installations, typically adding $100 to $500 to the project.

What should a whole-house generator estimate include?

A detailed estimate should clearly identify:

• The generator model and its rated capacity
• The automatic transfer switch
• Electrical work, including any panel upgrades
• Gas line work, if needed
• The concrete or composite pad
• Permits and inspection fees
• Labor for the full installation
• Startup, testing, and any manufacturer registration
• Warranty coverage — both the generator itself and the installation workmanship

If a quote gives you a single number without breaking down what’s included, ask the installer to walk you through it before approving anything.

Why do quotes vary so much between installers?

Two installers can quote very different prices for what sounds like the same job because they may be:

• Recommending different generator sizes or brands
• Including or excluding panel upgrades
• Quoting different gas line scope
• Including different warranty terms
• Pricing labor differently based on experience, location, or company overhead

Don’t assume a lower quote is automatically the better deal — ask what’s included before comparing the bottom-line numbers directly.

Are there ongoing costs after installation?

Yes. Beyond the upfront installation, expect to budget for:

• Periodic maintenance (oil changes, filter changes, similar to a small engine)
• Fuel costs when the generator actually runs (minimal for natural gas systems that only activate during outages, more relevant for propane systems)
• An annual service check, which many manufacturers recommend to keep the warranty valid

Ask what maintenance schedule the manufacturer recommends and whether the installer offers a service plan.

Does the size of your home affect the price directly?

Not directly — what affects the price is the size of the generator needed to power what you want backed up, which is related to your home’s electrical load, not simply its square footage. See What Size Generator Do I Need for My House? for why sizing shouldn’t be based on square footage alone.

How does this compare to a portable generator?

A whole-house standby system costs significantly more than a portable generator, both upfront and in installation complexity. See Portable vs Standby Generator for a fuller comparison of when each type actually makes sense for a given household — that decision should come before you commit to either system.

Get more than one estimate

For a project this significant, getting two or three estimates is worth the time. Give each installer the same information about what you want to power, and compare the complete scope — generator size, electrical work, gas work, pad, permits, and warranty — not just the final number. This is where knowing what to ask before hiring pays off.

Questions to ask before approving the installation

• What size generator are you recommending, and based on what load calculation?
• Does the estimate include a transfer switch and any necessary panel upgrades?
• Is gas line work included, and if so, what does it involve?
• Are permits and inspections included in the price?
• What warranty covers the generator, and what covers the installation itself?
• What ongoing maintenance will this system require?

The bottom line

A whole-house generator typically costs several thousand dollars installed, with many homeowners landing somewhere between $5,000 and $15,000, though your specific number depends on system size, fuel type, and how much electrical or gas work your home requires. Compare the complete scope of what’s included before deciding, and make sure the sizing behind the quote is based on your home’s actual needs rather than a generic recommendation.

Before You Fix, know what’s driving the cost before you approve a whole-house generator installation.