# Whole-house generator cost in 2026: standby prices by size

> A standby generator costs $6,000–$11,000 installed; a 22 kW unit runs about $9,500–$10,000 all-in. Sizes, fuel costs, transfer switches, portable and battery alternatives, upkeep.

- URL: https://2search.in/knowledge/articles/oct-26/whole-house-generator-cost
- Genre: Heating & cooling
- Country: United States
- Published: 2026-10-27
- Updated: 2026-10-27
- Publisher: 2search (https://2search.in)

> **Quick answer:** A natural-gas or propane **standby generator** typically costs **$6,000–$11,000 installed**. A **22 kW** unit — enough to run most average homes, often including central AC — usually lands near **$9,500–$10,000** all-in, and large or complex systems can reach **$15,000–$24,000**. Plan on **$200–$600 a year** for maintenance. A **portable generator with an interlock kit** is a cheaper partial-home option at roughly **$1,500–$3,500** total.

> **Key takeaways**
> - Size the generator from your **must-run loads**, especially **central AC, well pumps and electric heat**.
> - The **automatic transfer switch** is essential for safety and is often **$1,200–$1,600** installed.
> - **Natural gas** is cheapest to run and never runs out; **propane** needs a tank sized for multi-day outages.
> - **Load management** modules let a smaller generator run a bigger home.
> - Never run a portable generator **indoors or in a garage** — carbon monoxide kills.

Longer and more frequent power outages — from storms, heat waves and wildfires — have made standby generators a common home upgrade. This guide breaks down 2026 costs, helps you choose the right size, explains fuel choices, and compares generators with portable units and home batteries.



![Whole-house generator cost in 2026: standby prices by size Breakdown & Visual Guide](/images/articles/whole-house-generator-cost/diagram.svg)

## Standby generator cost by size

| Generator size | What it typically powers | Installed cost |
| --- | --- | --- |
| **10–14 kW** | Essentials: fridge, furnace fan, sump pump, lights, outlets, internet | $6,000–$9,000 |
| **17–20 kW** | Most of a typical home; smaller central AC with load management | $7,000–$11,000 |
| **22–26 kW** | Whole home for many 2,000–3,000 sq ft houses, including central AC | **$9,500–$14,000** |
| **30–48 kW** (liquid-cooled) | Large homes, multiple ACs, electric heat | $15,000–$24,000+ |

## What's in the price

| Item | Typical cost |
| --- | --- |
| Generator unit (22 kW air-cooled) | ~$5,500–$7,000 |
| **Automatic transfer switch** (ATS) | $1,200–$1,600 installed |
| Gas line from meter or propane tank | $400–$1,500 |
| Electrical work and wiring | $500–$2,000 |
| Concrete or composite pad | $150–$400 |
| Permits and inspection | $80–$450 |
| Gas meter upgrade (if needed) | $0–$1,000 (often free from the utility, but can take weeks) |
| Propane tank (if no natural gas) | $500–$3,000+ for 250–500 gallon tanks, or leased |
| Load management modules | $200–$600 each |

Prices are higher where **electrical panels need upgrading**, the generator must sit **far from the house**, or local codes need extra work.

## What size generator do you need?

1. **List must-run loads** and their running watts. Big ones to check:

| Load | Running watts (approx.) | Starting watts |
| --- | --- | --- |
| Central AC (3-ton) | 3,500–4,500 | 7,000–10,000+ |
| Heat pump (3-ton) | 3,500–5,000 | Higher (soft starters help) |
| Furnace blower | 600–1,000 | 1,200–2,000 |
| Well pump (1 hp) | 1,000–1,500 | 2,000–3,000 |
| Refrigerator | 150–250 | 700–1,200 |
| Sump pump (½ hp) | 800–1,000 | 1,500–2,500 |
| Electric water heater | 4,500 | 4,500 |
| Electric range | 3,000–8,000 | — |
| Lights, TV, internet, outlets | 1,000–2,000 | — |

2. **Add running watts**, plus the **biggest starting surge**.
3. Add **10–20%** headroom.

> **Example:** A 2,200 sq ft gas-heated home with a 3-ton AC: AC 4,000 W + furnace 800 W + fridge 200 W + sump 900 W + lights/outlets 2,000 W ≈ **7,900 W running**. AC start adds ~5,000 W surge → ~13,000 W peak. With headroom and future loads, a **17–22 kW** generator is a comfortable fit.

> **Tip:** A **soft-start kit** on your AC ($200–$400) cuts its starting surge, often letting you buy a smaller generator.

Many installers do a **load calculation** based on your panel and past electric bills — ask for it.

## Natural gas vs propane vs diesel

| Fuel | Pros | Cons | Running cost (22 kW at half load, rough) |
| --- | --- | --- | --- |
| **Natural gas** | Unlimited supply, cheapest per hour, no tank | Slightly lower output; needs adequate meter size | ~$1.50–$3 an hour |
| **Propane** | Works anywhere; stores for years | Need a big tank for long outages | ~$5–$9 an hour (about 1.8–2.2 gal/hr) |
| **Diesel** | Common on very large units | Fuel goes stale; louder; storage rules | Varies |

> **Example:** A 22 kW propane generator at half load burns about **2 gallons an hour**. A **5-day outage** (120 hours) needs about **240 gallons** — a **500-gallon tank** (filled to 80%) covers that with some to spare.

## Air-cooled vs liquid-cooled

- **Air-cooled** (most home units up to ~26 kW): cheaper, simpler, louder at full load.
- **Liquid-cooled** (usually 30 kW+): quieter, longer-lasting, for big homes and long run times; costs more.

## Maintenance and running costs

- **Annual service:** $200–$600 — oil and filter change, spark plugs, battery check, software updates.
- The generator runs a **weekly self-test** for 5–20 minutes, using a little fuel.
- Replace the **battery** every 3–5 years.
- With good care, standby generators often last **20–30 years** or **3,000+ hours**.

## Alternatives to a whole-house standby generator

| Option | Total cost | Pros | Cons |
| --- | --- | --- | --- |
| **Portable generator + interlock kit and inlet** | $1,500–$3,500 | Much cheaper; runs selected circuits | Manual setup in storms; refuelling; CO danger if misused |
| **Portable inverter generator** (extension cords only) | $500–$2,000 | Quiet, cheap | Few appliances; no hardwired circuits |
| **Home battery** (e.g., 13.5 kWh) | $10,000–$16,000 per battery | Silent, no fuel, works with solar | Limited run time for AC and heat; multi-day outages need solar |
| **Battery + solar** | $25,000–$45,000+ | Recharges daily | Highest cost; winter output lower |

Compare with [solar panel cost](/solar-panel-cost) if you're considering a battery.

## How to choose an installer

- Use a **factory-authorised dealer** for warranty support.
- Ask for a **load calculation**, permit handling and a **written warranty** (5–10 years is common).
- Confirm the **placement** meets code — usually at least **5 feet** from windows, doors and vents, and specific distances from gas meters.
- Ask about **maintenance plans** and response times after storms.

## Safety essentials

- Never connect a generator to your home without a **transfer switch or interlock** — **backfeeding** can kill utility workers.
- Install **carbon monoxide alarms** on every level.
- Keep portable generators **20+ feet** from the house, with the exhaust pointing away.
- Keep the area around a standby unit **clear of snow, plants and debris**.

## Frequently asked questions

### How much does a whole-house generator cost?

Usually $6,000–$11,000 installed for standard sizes; a 22 kW unit is often about $9,500–$10,000 all-in.

### What size generator do I need to run my whole house?

Many 2,000–3,000 sq ft homes need 20–26 kW to run everything including central AC. A load calculation gives the right answer.

### How long can a standby generator run?

On natural gas, as long as gas is supplied (with breaks for oil checks during very long outages). On propane, until the tank runs low.

### Does a generator add value to a home?

It can — buyers in storm-prone areas often value backup power. Exact value varies by market.

### Is a portable generator enough?

For essentials, often yes, with an interlock kit. For whole-house automatic backup, choose a standby unit.

### How loud is a standby generator?

Many air-cooled units run around 60–70 dB at a few metres — similar to a conversation or a loud AC unit. Weekly tests often run in a quieter mode.

### Do I need a permit to install a generator?

Usually yes — electrical, gas and sometimes zoning permits. Licensed installers typically handle them.

## Sources

- [ThePricer — How much does a standby generator cost](https://www.thepricer.org/how-much-does-a-standby-generator-cost/)
- [Ready.gov — Power outages and generator safety](https://www.ready.gov/power-outages)
- [Generac — Home standby generators](https://www.generac.com/)