Whole House Generator Cost (2026): Installed Prices

Quick answer: how much does a whole house generator cost?

Published whole house generator cost estimates vary because the sources do not measure identical project scope. Generac currently publishes a broad $8,000–$16,000 range including its generator, system equipment/materials, and installation. HomeGuide, in a guide published December 30, 2025, lists an average $6,000–$11,000 total for a whole-house generator and installation, and $9,500–$24,000 for longer distances or systems above 20 kW.

Those figures are planning references from different sources—not a Standby Generator Guide national average and not a quote for your property. The actual installed price depends on the exact generator and transfer equipment, fuel work, electrical work, site preparation, permits, inspections, local labor, and any service-panel or utility upgrades.

Whole house generator cost: separate equipment from installation

Whole house generator cost depends on much more than the generator itself. A product page may show a starting MSRP, but a completed project can also involve a transfer switch, wiring/conduit, fuel connection or tank, site/pad preparation, permits, inspections, startup, and related labor. Which items are included depends on the model/package, property, jurisdiction, and installer. A headline unit price cannot establish the full installed cost.

National planning estimates differ. Generac’s installation guide states a broad $8,000–$16,000 range that includes its generator, system equipment/materials, and installation. HomeGuide, in a guide published December 30, 2025, lists an average $6,000–$11,000 total for a whole-house generator and installation, and $9,500–$24,000 for longer distances or systems above 20 kW. These are sources’ different estimates—not a blended “national average,” a bid, or a promise about any one property.

Use the ranges to decide what questions to ask; use current local proposals to budget the actual project. Standby Generator Guide does not sell generators or arrange installer quotes.

Selected current model MSRPs checked October 4, 2026

The following are exact manufacturer model-page starting prices, where the page provides one. They are not equivalent system prices: the switch/bundle scope differs or is not established on some pages. Product pricing, availability, and bundle contents can change.

The KOHLER manufacturer pages show distinct 26RCA and ATS-inclusive 26RCAL starting MSRPs, and Generac model-family sheets describe a 200 A ATS in bundled models. Those examples demonstrate why a starting price must be matched to the exact package. Do not infer dealer inclusions from a headline price—require exact model numbers and components in writing.

Published installed ranges: keep source scope visible

The gap between sources is a reason to compare what each estimate includes, not to average the values. A long gas run, service-panel work, constrained siting, larger capacity, or unusual permitting can place a project outside a headline planning range.

What changes a quote

• Equipment scope: exact model, fuel rating, standby output, transfer switch and service rating, load management, monitoring, battery, and any package-specific accessories.
• Electrical path: panel configuration, circuit selection, switch location, wire/conduit length, trenching, panel changes, and commissioning.
• Fuel path: existing fuel type/capacity, pressure and flow at generator load, pipe sizing, distance, trenching, meter/regulator changes, and propane storage if used.
• Site work: approved base/pad, grading, drainage, access, clearances, distance to openings, vegetation, service access, and any special lifting needs.
• Local approval: permits, inspections, utility coordination, property/HOA restrictions, and local code requirements.
• Labor and service: contractor availability, included startup/transfer testing, warranty registration, and who provides future service.

Published planning references for individual line items

HomeGuide lists the following broad planning figures in its cited cost guide. They are not guaranteed local prices, and the items should not simply be added together: estimates may overlap with each other or with an installer’s bundled scope.

Source and update date: HomeGuide’s whole-house generator cost guide, published December 30, 2025; accessed October 4, 2026.

Compare quotes with this checklist

• Are the generator model number, fuel rating, output, and phase identical?
• Is an ATS/interlock included? Record its model, amperage, and service-entrance rating, if applicable.
• Which circuits and load-management devices are included, and which appliances are excluded or sequenced?
• Are fuel capacity/pressure checks, line work, regulator/meter changes, and leak testing included?
• Are wiring, trenching, panel work, pad/site preparation, permit fees, inspections, and startup/commissioning included?
• Are allowances, exclusions, taxes, payment schedule, warranty responsibilities, and change-order terms stated?

Compare at least two written proposals on the same equipment and scope. Ask each contractor to identify assumptions, exclusions, and any work that depends on a utility or permit authority. For a printable-style side-by-side worksheet, use the dedicated 16-line standby generator quote checklist.

Common whole house generator cost questions

How much does a whole house generator cost installed?

An installed price can include the generator, transfer switch, electrical work, fuel connection, pad or site preparation, permits, inspections, startup, and related labor. Published ranges above provide context, but a site-specific written proposal is the only useful way to price the actual property.

What is the average cost of a whole house generator?

HomeGuide publishes a $6,000–$11,000 average total in its December 2025 guide, while Generac publishes a different $8,000–$16,000 planning range for its generator, system equipment/materials, and installation. Because the sources use different scope and methodology, we do not blend them into a new average.

How much does whole house generator installation add?

There is no fixed installation add-on. Fuel-line distance and capacity, electrical routing, transfer equipment, panel work, trenching, pad/site work, permits, and local labor can materially change the project. See the whole house generator installation cost breakdown for the separate work categories.

Why can two generator quotes be thousands of dollars apart?

Two totals may cover different equipment and work. Compare the exact generator and ATS model numbers, backed-up loads, fuel and electrical scope, permits, site work, commissioning, warranty responsibilities, allowances, and exclusions before treating the lower number as the lower-cost project.

How much do 22 kW and 26 kW whole house generators cost?

Equipment prices depend on the exact model and whether the published price includes transfer equipment or another bundle. The current model-price table above keeps each manufacturer-listed starting MSRP attached to its exact configuration; use that rather than assuming one universal price by kilowatt rating.

Fuel and maintenance after installation

Fuel use depends on exact model, fuel, load, fuel composition/pressure, and run time. Use the manufacturer’s fuel-consumption table for the actual model and current local utility or propane pricing; a half-load test value is not an hourly household bill. Our model data pages show cited test points and conditions.

Service schedules also differ. Follow the exact generator owner/maintenance manual and service provider’s instructions. HomeGuide lists annual maintenance estimates of $200–$650 in its 2025 guide, but local service plans, included labor, parts, operating hours, and battery replacement can change actual costs. Get a current written service quote rather than treating a national estimate as a required fee.