Generator cost by size
The table below is the generator calculator’s 2026 installed range including the unit, an automatic transfer switch, a short gas-line and wiring run, a pad, and permit — a complete standby install, not just the generator. Portable figures assume a manual transfer switch.
| Generator | Installed range | Covers |
|---|
| Portable (manual) | $4,700 – $8,300 | A few circuits; you start and connect it |
| 8 kW standby | $9,600 – $16,900 | Essentials: heat, fridge, well, some outlets |
| 14 kW standby | $11,200 – $19,500 | Most of a small-to-mid home (most common) |
| 22 kW standby | $13,400 – $23,300 | A whole large home incl. central AC |
| Liquid-cooled 25 kW+ | $21,000 – $36,700 | Large homes, long runtimes, light commercial |
What size generator do you need?
- 8–10 kW — runs the essentials during an outage: furnace or boiler, refrigerator, well pump, sump pump, and a few lights and outlets. Good for a small home or a “keep the basics on” budget.
- 14 kW — the most-installed size. Runs most of a small-to-medium home, often including one central AC with a load-management module.
- 22–24 kW — whole-home coverage for a larger house, including central AC, electric range, and multiple large loads at once.
- Liquid-cooled 25 kW+ — big homes, very long runtimes, or light commercial; these run cooler and last longer under continuous load.
An electrician sizes the unit from your panel and the loads you want covered. Oversizing wastes money; undersizing means the generator sheds loads during a heavy draw.
Frequently asked questions
How much does a whole-house generator cost installed?
A standby whole-house generator runs about $9,600–$23,300 installed in 2026 depending on size — $9,600–$16,900 for an 8 kW, $11,200–$19,500 for a common 14 kW, and $13,400–$23,300 for a 22 kW — including the unit, automatic transfer switch, gas and electrical connections, a pad, and permit. Liquid-cooled units for large homes run $21,000–$36,700.
What size generator do I need for my house?
Most homes use a 14 kW standby unit, which runs a small-to-medium home including one central AC. An 8–10 kW unit covers just the essentials (heat, fridge, well, some outlets); 22–24 kW covers a large home with central AC and big loads. An electrician sizes it from your electrical panel and the loads you want backed up.
Is a standby or portable generator cheaper?
A portable is far cheaper — about $4,700–$8,300 installed with a manual transfer switch, versus $9,600–$23,300 for a permanently installed standby. But a portable only powers a few circuits, must be rolled out, fueled, and started by hand, and can’t run unattended. A standby starts automatically and powers the house; you pay for that convenience.
How much does the transfer switch add?
An automatic transfer switch is built into the standby ranges above — it is what lets the generator start and power your home automatically during an outage. Choosing a manual switch instead saves several hundred dollars but means you operate the changeover by hand every time the power goes out.
Does a whole-house generator need a permit?
Yes. A standby generator is permitted electrical and gas work in nearly every jurisdiction, and most areas require an inspection of the gas connection and the transfer switch wiring. A licensed electrician (and often a gas fitter) does the install; the permit and inspection are included in the ranges above.
Which generator should you pick?
- Just want the essentials on a budget? A portable with a manual transfer switch, or an 8–10 kW standby.
- Want the house to stay on automatically? A 14 kW standby — the most common whole-home choice.
- Large home with central AC and big loads? 22–24 kW.
- No natural gas? Budget for a propane tank on top of the unit.
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