how much does a whole-house generator cost (real numbers, not the sticker price)

I'm going to tell you the number that nobody puts on the first page of their website: the real cost of a whole-house standby generator, installed and running, with nothing left out.

Because the sticker price is not the real price. Everyone gets surprised by this. You see a Generac Guardian on Home Depot's website for $5,200 and you think that's the ballpark. It is not the ballpark. It is not even in the same zip code as the ballpark.

The generator unit is roughly half the cost. Sometimes less. The other half is the stuff that makes it actually work: the transfer switch, the concrete pad, the electrical labor, the gas line, the permits, and the inevitable thing your electrician finds when he opens your panel that "needs to be brought up to code."

Here's what you're actually looking at.

Let me break every piece of that number down so you know exactly where your money goes.

the generator unit itself

This is the part everyone shops for and the part that matters least in the total equation. That sounds backwards, but hear me out — the price spread between generator sizes is smaller than the price spread between installation scenarios. A 14kW and a 24kW unit might differ by $3,000-$4,000. But a simple install versus a complicated one can differ by $5,000 or more.

That said, here's what the units themselves cost as of early 2026:

• 14kW (entry level): $4,000 - $5,500. Covers essential circuits only. Good for a small home or if you're fine without AC during an outage.
• 20kW (sweet spot): $5,500 - $7,500. Handles most homes up to 3,000 sq ft with central air. This is what I recommend for most people.
• 22-24kW (large home): $6,500 - $9,000. For bigger homes, multiple AC zones, or if you have electric appliances you refuse to give up during an outage.
• 25kW+ (overkill territory): $8,000 - $15,000. Commercial-grade units. You need this if you have a very large home, a shop, or you're running equipment that demands serious power.

These are retail prices for the unit alone — no installation, no accessories. Generac is the cheapest, Kohler and Cummins run 15-25% more for comparable output. I break down the brand differences in my Generac vs Kohler comparison.

If you're not sure what size you need, don't guess. I wrote a full guide on what size generator you actually need and built a sizing calculator that walks you through it in about two minutes.

automatic transfer switch (ATS)

The transfer switch is the box that sits between the utility power and your electrical panel. When the power goes out, it detects the loss, signals the generator to start, and switches your house over — usually within 10-30 seconds. When utility power comes back, it switches you back and shuts the generator down.

Without it, you have a very expensive lawn ornament.

Cost: $500 - $2,000

Some generators come bundled with an ATS. Generac includes one with most of their home standby models. If yours doesn't include one, or if you need a higher-rated switch (200A vs 100A), budget $800-$2,000 for a standalone unit. Your electrician will have a preference — listen to them on this one, because the ATS is the thing that fails most often and you want one they know how to service.

concrete pad

Your generator needs to sit on something. Most installers pour a concrete pad or use a pre-cast GenPad. Some use gravel with composite pads. Code in most areas requires the generator to be on a level, non-combustible surface at least 18 inches from the house (sometimes more — check your local code).

Cost: $200 - $500

This is one of the cheaper line items, but don't skip it. I've seen people set generators on bare ground or wooden platforms. The vibration alone will cause problems within a year, and you're putting a machine that runs on gasoline or propane on top of something flammable. Don't be that person.

electrical work and installation labor

This is the big one. This is where your final number lives or dies.

Cost: $3,000 - $6,000

Installation labor covers:

• Setting the generator on the pad and securing it
• Installing and wiring the automatic transfer switch
• Running conduit from the generator to the transfer switch to the panel
• Any panel upgrades or modifications needed
• Load testing and commissioning
• Programming the transfer switch and weekly exercise schedule

A straightforward install — generator goes next to the house, panel is close, no upgrades needed — runs $3,000-$4,000 in labor. A complicated install — generator far from the panel, panel needs a subpanel or upgrade, old wiring that needs replacing — can hit $5,000-$6,000 easily.

The most common surprise? Your electrical panel. If you have a Federal Pacific, Zinsco, or Challenger panel — or any panel over 25 years old — your electrician may require (or strongly recommend) a panel replacement before they'll connect a generator to it. That's $1,500-$3,000 on top of everything else. It's the right call, but it hurts.

gas line or propane tank

Your generator runs on fuel. If you have natural gas service, you'll need a dedicated gas line run from your meter to the generator. If you don't have natural gas, you'll need a propane tank.

Cost: $500 - $3,000

The spread here is wide because the scenarios are wildly different:

• Natural gas, short run (under 30 feet): $500 - $1,200. This is the best-case scenario. A plumber runs a new line from your gas meter to the generator location. Simple, fast, cheap.
• Natural gas, long run or line upgrade: $1,200 - $2,500. If the generator is far from the meter, or if your existing gas line can't handle the additional load, the line needs to be upsized. The gas company may need to upgrade the meter too, which can add time and cost.
• Propane tank (new): $1,500 - $3,000. Buying a 500-gallon underground or above-ground propane tank plus the line to the generator. You can lease a tank from a propane supplier for less upfront, but you're locked into buying their propane — which is almost always more expensive per gallon.
• Propane (existing tank): $500 - $1,000. If you already heat with propane, you just need a line run from the existing tank to the generator. Make sure your tank is big enough — a 20kW generator burns about 2-3 gallons of propane per hour at full load.

permits and inspections

Cost: $200 - $500

Almost every jurisdiction requires permits for a standby generator installation. Usually an electrical permit and a gas/plumbing permit. Some areas require a building permit too. Your installer should pull these — if they suggest skipping permits to save money, fire them immediately. Unpermitted generator installations can void your homeowner's insurance, create problems when you sell the house, and in some areas, result in fines.

The permit cost itself is minor. The real cost is time — inspections can add a week or two to your project timeline.

optional but worth considering

whole-house surge protector

$200 - $400 installed

When utility power comes back on after an outage, the initial surge can fry electronics. A whole-house surge protector at the panel is cheap insurance. If your electrician is already in the panel for the generator install, adding this is minimal extra labor. I consider this nearly mandatory, not optional.

load management module

$400 - $800 installed

A load management module lets a smaller generator handle a bigger house by intelligently cycling loads. Instead of running your AC and your electric dryer at the same time, it staggers them. This means you might be able to buy a 20kW unit instead of a 24kW unit and save $1,000-$2,000 on the generator itself. Generac calls theirs "Smart Management Modules." They work well. Worth discussing with your installer.

the full cost breakdown (table)

Here's what a complete installation looks like at four different generator sizes, assuming natural gas and a moderately complex install:

If those ranges look wide, it's because they are. Two houses on the same street can have a $5,000 difference in installation cost depending on panel age, gas line distance, and local code requirements. That's reality.

what affects your final cost

Here's why your neighbor paid $12,000 and you're getting quoted $18,000 for the same generator. It almost always comes down to one or more of these:

your region

Labor rates vary wildly. A generator install in rural Tennessee might cost $3,000 in labor. The same install in suburban Connecticut might cost $5,500. Permits are cheaper in some areas and more expensive in others. If you live somewhere with high demand after recent storms, prices spike further — installers can charge what they want when everyone on the block wants a generator at the same time.

fuel type

Natural gas is the cheapest to connect. Propane with an existing tank is next. Propane requiring a new tank is the most expensive. If you're in a rural area without natural gas service, factor in $1,500-$3,000 for the propane setup.

electrical panel age and condition

This is the number-one cost wildcard. If your panel is 30 years old, undersized, or a known problem brand (Federal Pacific, I'm looking at you), it needs to go. Panel replacement: $1,500-$3,000. If your panel is recent, 200A, and in good condition, this isn't a factor. But about 40% of the homes I've seen need some kind of panel work.

distance from gas meter to generator location

Every foot of gas line costs money. If your gas meter is on the front of the house and the ideal generator location is in the back, you're paying for 50+ feet of gas line plus trenching. Some homeowners move the generator location closer to the meter to save $500-$1,000. Worth considering if your site allows it.

local code requirements

Some jurisdictions are stricter than others. Required setbacks from property lines and structures vary from 5 feet to 20 feet. Some areas require sound attenuation if you're close to a neighbor. HOAs add another layer of rules. Your installer should know local code inside and out — if they don't, find one who does.

time of year and demand

Buying a generator after a hurricane or ice storm is the most expensive time. Every installer is booked for months, equipment is backordered, and prices are 10-20% higher than off-season. If you're planning ahead (and you should be), buy in late winter or early spring when demand is lowest. That's when I got mine.

annual maintenance costs

Your generator is an engine. It needs maintenance like any engine. Skip this and you'll find out the hard way — usually during the outage when you need it most.

Annual maintenance cost: $200 - $500/year

What's included:

• Oil and filter change: Twice a year, or every 200 hours of operation. About $50-$80 if you do it yourself, $150-$200 if you pay someone.
• Air filter: Once a year. $15-$30.
• Spark plugs: Every 2 years. $20-$40.
• Coolant check (liquid-cooled units): Annual. Minimal cost unless you need a flush.
• Battery replacement: Every 2-3 years. $50-$80. The starter battery is a common point of failure. Replace it proactively.
• Annual service contract: $200-$350/year. Your dealer comes out, does everything above, runs a load test, and checks for issues. Worth it if you're not mechanically inclined.

Most standby generators run a weekly self-test — usually 15-20 minutes at low load. This burns a tiny amount of fuel and keeps the engine from sitting idle too long. The fuel cost for weekly tests is negligible — maybe $10-$20/year on natural gas.

fuel costs during outages

This is the cost nobody thinks about until day three of an outage when they're doing mental math at the gas meter.

Fuel consumption depends on load. Your generator won't run at full capacity the entire time (unless your house is wildly undersized for the unit). Typical consumption at 50% load:

• 20kW on natural gas: ~200-250 cubic feet per hour. At $1.50/therm, that's roughly $3-$4/hour, or $35-$50/day.
• 20kW on propane: ~1.5-2 gallons per hour. At $2.50-$3.00/gallon, that's roughly $4-$6/hour, or $50-$70/day.
• 20kW on diesel (if applicable): ~1-1.5 gallons per hour. At $3.50-$4.00/gallon, that's roughly $4-$6/hour, or $45-$65/day.

During a 3-day outage on natural gas, you're spending $100-$150 in fuel. On propane, $150-$210. That's real money, but compare it to a hotel for three nights ($300-$600), a chest of spoiled food ($200-$400), or a burst pipe from a dead sump pump ($5,000-$15,000).

The fuel costs are not the reason to hesitate.

financing options

Dropping $15,000 at once isn't something most people do casually. Here are the ways people pay for this:

• Cash/savings: Cheapest option overall. No interest, no payments. If you can do this, do it.
• Home equity loan/HELOC: Low interest rates (currently 7-9%), tax-deductible interest in some cases. This is the smart financing option if you have equity. The generator adds to your home value, so you're borrowing against an asset to create an asset.
• Dealer financing: Generac, Kohler, and many installers offer 12-60 month financing. Rates vary from 0% promotional (usually 12 months) to 12-15% APR. Read the fine print on promotional rates — if you don't pay it off in the promo period, they backcharge interest from day one.
• Personal loan: Rates from 8-15% depending on credit. Simple, fast, no home equity required. Decent option if you need the generator now and can pay it off in 2-3 years.
• Credit card: Do not do this. 20%+ interest on a $15,000 purchase is financial self-harm. The only exception is if you have a 0% intro APR card and the discipline to pay it off before the rate kicks in.

what you're really paying for

Let's do the math that actually matters.

The average extended power outage (12+ hours) costs a typical homeowner $500-$2,000 when you add up spoiled food, emergency supplies, missed work, hotel stays, and property damage from loss of sump pumps, HVAC, or medical equipment. A bad one — burst pipes, flooded basement, multi-day displacement — can cost $10,000 or more.

If you experience two serious outages per year (and in many parts of the country, that's conservative), you're looking at $1,000-$4,000 in annual costs or risks from not having backup power.

A $15,000 generator with $300/year in maintenance pays for itself in 4-8 years just on avoided losses. And it lasts 20-30 years with proper care.

But that's the rational math. The real reason people buy generators is the 2 AM math. The ice storm math. The "my kid has a nebulizer and the power just went out" math. The "I'm 68 years old and I can't spend three days in a cold house" math.

That math doesn't fit on a spreadsheet.

You're not paying $15,000 for a machine. You're paying $15,000 to stop worrying. And if you've been through a bad outage, you already know that's worth it.

how to save money (without cutting corners)

I am not going to tell you to skip the permit or hire your cousin who "knows electrical." But there are legitimate ways to reduce costs:

• Buy off-season. February through April is when prices and wait times are lowest.
• Get three itemized quotes. Compare line by line. Challenge any line item that's significantly higher than the others.
• Consider load management. A load management module ($400-$800) can let you buy a smaller generator, saving $1,000-$2,000.
• Locate the generator near the gas meter and panel. Every foot of conduit and gas line costs money.
• Pour your own pad. A concrete pad is one thing a handy homeowner can do themselves. Save $200-$300.
• Ask about package deals. Some dealers offer discounts if you also buy a maintenance contract or whole-house surge protector.
• Check for utility rebates. Some utilities offer rebates or incentives for standby generators, especially if you allow them to cycle your unit during peak demand. Not common, but worth asking.

what I actually paid

I'll show mine since I'm asking you to trust my numbers. My most recent install (2024) was a 22kW Generac Guardian on natural gas for a 2,800 sq ft house:

• Generator unit (22kW Generac Guardian): $7,200
• 200A transfer switch (included with unit): $0
• GenPad composite pad: $280
• Electrical labor and installation: $4,100
• Gas line (35 ft run from meter): $950
• Permits (electrical + gas): $350
• Whole-house surge protector: $280
• Total: $13,160

That was a relatively clean install. Panel was already 200A and in good shape. Gas meter was on the same side of the house. No HOA restrictions. Three quotes ranged from $12,800 to $16,400 for the same generator. The $16,400 guy was marking up the generator itself by $2,500 — I only caught it because I insisted on itemized quotes.

If you want to see what I recommend for most homes, I put together a ranked list of the best whole-home generators with specific model recommendations by house size and budget.