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Standby Generator Cost Calculator
A whole-house standby generator installs for $5,750–$29,400, and the machine is only about half of it. A 20–24 kW unit is $5,000–$6,500; the automatic transfer switch behind it is another $2,700–$3,700. Price every line separately below, including the gas run.
Standby Generator Cost Calculator
Educational calculators — always consult a licensed professional before making financial decisions.
Measured in kilowatts. The machine is only about half the total bill.
$5,000–$6,500 for the machine. Bob Vila's own words: about 20 to 24 kW «can power most of a home's appliances».
Total installed cost
$10,250 – $14,900
20–24 kW standby generator
The generator is only 46% of this estimate, and the automatic transfer switch alone is 25%. This is the number to take away: published generator prices quote the machine, and the machine is about half the project. A quote that does not name the transfer switch separately is not a complete quote.
What this size covers — the publisher's own words
Bob Vila states that a generator of about 20 to 24 kW «can power most of a home's appliances». Note this is a slightly more cautious claim than Fixr makes for 18 kW.
This calculator does not compute a size from your circuits, because none of its sources publishes appliance wattages and it will not invent them. A licensed electrician's load calculation is the real answer, and it is worth having before you buy.
This estimate includes a fuel connection at the machine but no gas line run from your meter. If the generator will sit away from the meter, go back and add the distance — at $20–$25 a foot before trenching, a thirty-foot run is another $600–$750 and a hundred-foot run is thousands.
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A $5,000 generator is never a $5,000 project
Every published generator price you will find quotes the machine, because the machine is the product with a model number on it. But a standby generator is not an appliance you plug in. It is a second electrical supply for your house, and connecting a second supply safely is most of what you are paying for.
The biggest single piece of that is the automatic transfer switch. Its job is to disconnect your house from the grid and connect it to the generator when the power fails — automatically, in seconds, and in a way that can never push generated power back up the utility line into a lineman working on it. That is a serious piece of switchgear and it is priced accordingly: $2,700–$3,700 with labour.
Add the electrical run from the machine to your panel, a bed for it to stand on, a fuel connection and a permit, and you have roughly the price of the generator again before anyone has run a foot of gas pipe. The calculator above reports the machine as a percentage of the total for exactly this reason — it is the fastest way to see whether the quote in front of you is complete.
The two costs buyers do not anticipate
| Line item | Cost | Source |
|---|---|---|
| Automatic transfer switch | $2,700–$3,700 | Fixr, unit and labour together |
| Gas line run | $20–$25 / ft | Bob Vila, generator-specific rate |
| Trenching that run | $4–$12 / ft | Bob Vila, priced separately from the pipe |
| Electrical run to the panel | $1,000–$2,000 | Fixr |
| Equipment bed / pad | $500–$1,000 | Fixr |
| Fuel connection at the unit | $1,000–$1,500 | Fixr |
The gas run is the one people miss most often, because it is invisible until someone measures the distance from your meter to where the machine will stand. At $20–$25 a foot — the highest per-appliance rate in Bob Vila's table, because a generator needs a bigger pipe than a stove — a thirty-foot run beside the house is another $600–$750, and a hundred-foot run across a yard to a detached position is $2,000–$2,500 before it is buried.
This calculator will not size your generator, and here is why
The right way to pick a kilowatt rating is a load calculation: add up the running watts of the circuits you want covered, then add the starting watts of anything with a motor, because a well pump or an air conditioner briefly draws several times its running load at the moment it kicks in. Get that wrong on the low side and the generator trips out during the outage you bought it for.
Doing that here would mean publishing an appliance wattage table. None of the three sources behind this page publishes one, so building the feature would mean inventing the numbers — and an invented wattage table dressed up as a sizing tool is worse than no sizing tool, because it looks authoritative.
What this page does instead is show you each tier's own publisher's coverage claim, verbatim, so you can see what is actually being asserted — including where the two publishers disagree. Fixr says an 18 kW machine covers a 2,000 sq ft home with heating and cooling; Bob Vila says 20–24 kW covers “most of a home's appliances”. Those are not the same claim, and noticing that is more useful than a false precision.
What this calculator assumes, stated plainly
- The labour figures come from a 2022 page, and that is the oldest source on this site. Fixr's installation breakdown (page updated 19 August 2022) is the only fetched source that itemises the transfer switch, the wiring, the bed and the piping separately, which is what this calculator is for. Four-year-old labour rates almost certainly understate today's. Read the installation lines as a floor.
- The two sources disagree wildly on the total. Fixr says $10,000–$20,000 with a $15,000 average; Bob Vila says $1,524–$8,658 with a $5,090 average. They barely overlap, most likely because they describe different scopes. Neither is used as this page's headline — the headline is the span of this calculator's own configurations, each a sum of individually published components.
- The gas run is optional because it can double-count. The fuel connection line already covers the hook-up at the machine. Add the run only when the generator sits a real distance from the meter, or you will pay twice for a short connection.
- Portable generators are not priced here. They are a different product — no switchgear, no permanent installation, no automatic start — not a cheaper version of this one.
- Not modelled: a propane tank and its installation where there is no natural gas supply, an electrical sub-panel if the existing one cannot take the switchgear, annual servicing, rock excavation for the pad, and the cost of an electrician's load calculation itself. Each is real; none is priced in a form that can be applied to a specific job from these sources.
Related calculators
A generator and a service upgrade are frequently quoted in the same visit, since both are work at the main panel — the electrical panel upgrade cost calculator prices that side by amperage, and doing the two together is much cheaper than doing them a year apart. If the reason you want backup power is solar rather than outages, the solar panel installation cost calculator prices the alternative approach to the same problem. And if the outage risk you are actually insuring against is a flooded basement when the sump pump loses power, the sump pump & French drain cost calculator prices a battery backup at $150–$250 — which solves that one problem for a fraction of a generator.
Before you pick a kilowatt tier, read our guide on standby generator sizing and placement rules — it covers the running-watts-vs-starting-watts math no cost guide publishes, and the NFPA 37 clearances, property-line setbacks and noise ordinances that decide where you are legally allowed to put the machine.
Methodology & sources
The cost figures on this page are generated from a single, sourced cost-data file (A permanently installed residential standby generator: the machine, the automatic transfer switch that swaps the house over when the grid fails, the electrical run from generator to panel, the bed or pad it stands on, and the fuel connection. The generator VARIANTS below are the machine alone, by kilowatt tier; every other cost is a separately named line item, because those are the ones buyers do not see coming. Portable generators are NOT priced here — they are a different product with no switchgear and no permanent installation.). The kilowatt ladder is Bob Vila's (page updated 2024-06-29), used whole rather than blended, and it prices the MACHINE ONLY. The installation decomposition — transfer switch $2,700-$3,700, wiring to the house $1,000-$2,000, equipment bed $500-$1,000, fuel piping $1,000-$1,500 — is Fixr's (page updated 2022-08-19), which is the oldest source on this site and should be read as such. The permit at $50-$200 is Bob Vila's. The two publishers disagree violently on the total project cost — Fixr $10,000-$20,000 against Bob Vila $1,524-$8,658 — most likely because they describe different scopes, so neither is used as the headline; the headline is the span of this calculator's own minimum and maximum configurations, each a sum of published components. Generator sizing is NOT computed from circuit loads, because no cited source publishes appliance wattages and this page does not invent them. Last verified September 2026.
- Bob Vila — How Much Does a Whole-House Generator Cost to Install? (page updated 29 Jun 2024) — retrieved 2026-09-02
- Fixr — Cost to Install Whole House Generator / Standby Generator Prices (page updated 19 Aug 2022) — retrieved 2026-09-02
- Bob Vila — Gas Line Installation Cost: A Homeowner Budgeting Guide (page updated 29 Feb 2024) — retrieved 2026-09-02
Frequently asked questions
How much does a whole-house standby generator cost installed?+
A complete installation runs $5,750–$29,400 — the machine plus the switchgear, wiring, bed and fuel connection that make it work. The generator itself is only about half of that: $5,000–$6,500 for a 20–24 kW unit, $4,000–$5,500 at 14–18 kW, and $2,000–$3,500 for a 7.5–10 kW partial-coverage machine. The rest is an automatic transfer switch at $2,700–$3,700, the electrical run to the panel at $1,000–$2,000, an equipment bed at $500–$1,000, the fuel connection at $1,000–$1,500 and a permit at $50–$200.
Why is a standby generator installation so much more than the generator?+
Because a standby generator is not an appliance you plug in — it is a second electrical supply for your house, and connecting a second supply safely is most of the work. The automatic transfer switch is the biggest single piece of it: it disconnects your house from the grid and connects it to the generator when the power fails, and it does that automatically and in a way that cannot ever backfeed the utility line and electrocute a lineman working on it. Fixr prices that switch at $2,700–$3,700 with labour. Add the electrical run from the machine to your panel, a bed for it to stand on and a fuel connection, and you have roughly the price of the generator again. On a typical configuration the machine is about 45% of the bill and the transfer switch alone is close to a third.
How much does it cost to run a gas line to a generator?+
Bob Vila publishes $20 to $25 per linear foot for a generator gas line specifically — the highest per-foot rate in its per-appliance table, because a generator draws far more gas than a stove or a dryer and needs a larger pipe to feed it. Trenching that line, which any run crossing open ground will need, is a separate $4 to $12 per foot depending on what the trench has to go through. So a thirty-foot run beside the house is roughly $600–$750 for the pipe plus $120–$360 to bury it, and a hundred-foot run to a detached position is $2,000–$2,500 plus $400–$1,200. This is the second of the two costs buyers routinely fail to anticipate, after the transfer switch.
What size standby generator do I need?+
The honest answer is that a licensed electrician should do a load calculation, adding up the running and starting watts of the circuits you want covered — starting watts matter because a well pump or an air conditioner briefly draws several times its running load when it kicks in. As a rough published guide, Fixr describes an 18 kW machine as powering a 2,000 square foot home including heating, cooling, hot water, lighting and appliances, while Bob Vila says a unit of about 20 to 24 kW can power most of a home's appliances. Note those two claims do not quite agree, which is itself worth knowing. Below roughly 10 kW you are buying partial coverage — a fridge, a furnace fan, a well pump and some lighting — rather than a whole house.
Do the published generator cost guides agree with each other?+
On the total project, no, and the gap is large enough that you should know about it before you budget. Fixr puts a whole-house generator installation at $10,000–$20,000 with a national average of $15,000. Bob Vila puts the typical range at $1,524–$8,658 with an average of $5,090. Those barely overlap. The most likely explanation is scope rather than error — Bob Vila's range reads like a machine plus a light installation, Fixr's like a full whole-house job with switchgear and fuel work. Because they cannot both describe the same project, neither is used as this calculator's headline; the headline is the span of the calculator's own configurations, each one a sum of individually published components.
Is a portable generator a cheaper alternative?+
It is a genuinely different product rather than a cheaper version of the same one, and this calculator does not price it. A portable generator is a machine you wheel out, start by hand and run extension cords from, or connect through a manual transfer switch you operate yourself. A standby generator is permanently installed, runs on your gas supply so it never needs refuelling, and starts itself within seconds of an outage whether or not anyone is home. If nobody will be at the property during outages, or if the reason you want backup power is a sump pump or a medical device, the automatic start is the entire point and a portable is not a substitute for it.
Standby Generator Cost Calculator is built and maintained by the RealCostIQ editorial team. Cost ranges and rates are checked against published industry data and contractor quotes, and revised when the underlying figures move. Read our data methodology or more about who builds this. Every calculation runs in your browser — no account, and none of your inputs are stored.
Cost ranges and rates here are checked against contractor quotes and published industry data. If a number still looks off, email Support@RealCostIQ.com and we'll review and fix it.