What Size Generator Do I Need for My House in Texas?
Quick Answer
Most Texas homes need a 16 to 22 kW standby generator for whole-home coverage. A 10–14 kW generator covers essential circuits only. Larger homes with multiple HVAC systems, pools, or EV chargers need 24 kW or more. The right size depends on your home's electrical load — we perform a free load calculation to determine exactly what you need.
After Winter Storm Uri in 2021 and several ERCOT grid emergencies since, whole-home generators have become one of the most requested electrical projects in Austin and the Texas Hill Country. But one of the first questions homeowners ask is: what size do I actually need?
Generator sizing isn't guesswork — it's math. The right size depends on your home's square footage, HVAC system, appliances, and what you want to power during an outage. This guide breaks it all down so you can make an informed decision before you buy.
Generator Sizing by Home Size — Texas Guide
| Home Size | Recommended Generator | What It Powers |
|---|---|---|
| Up to 1,500 sq ft | 10–14 kW | Essential circuits — HVAC, fridge, lights, outlets |
| 1,500 – 2,500 sq ft | 16–20 kW | Most of the home — HVAC, kitchen, well pump, home office |
| 2,500 – 3,500 sq ft | 20–22 kW | Whole home — all circuits, multiple HVAC zones |
| 3,500+ sq ft | 24–26 kW+ | Large homes with pool, workshop, or multiple systems |
| Multiple HVAC + pool + EV charger | 30–48 kW | High-demand homes — often two panels |
These are general guidelines. Your actual requirement depends on your specific appliances and how much of your home you want powered during an outage. A licensed electrician performs a load calculation to give you an exact recommendation.
Generator Size Options Explained
Essential Coverage
10–14 kW- One HVAC system (partial)
- Refrigerator & freezer
- Lights & select outlets
- Sump pump
- Garage door opener
- Phone & device charging
Most Popular
16–22 kW- Full HVAC coverage
- All lights & outlets
- Kitchen appliances
- Well pump
- Home office
- Level 1 EV charging
- Washer & dryer
Whole-Home
24–48 kW- Multiple HVAC systems
- Pool & spa equipment
- Level 2 EV charger
- Large homes 3,500+ sq ft
- Guest house or barn
- Workshop equipment
- Electric range & oven
How Generator Sizing Actually Works
Generator sizing is based on two numbers: running watts and starting watts. Running watts is the power an appliance uses during normal operation. Starting watts is the surge of power needed to start the appliance — motors (like your AC compressor) can require 2 to 3 times their running wattage to start.
This is why undersized generators fail during Texas summers. If your 14 kW generator is already running your AC, refrigerator, and lights, it may not have enough headroom to start the washing machine or a second HVAC zone — and it will shut down trying.
Key Appliance Wattages for Texas Homes
| Appliance | Running Watts | Starting Watts |
|---|---|---|
| Central AC (3-ton) | 3,500W | 7,000–9,000W |
| Central AC (4-ton) | 4,500W | 9,000–11,000W |
| Well pump (1 HP) | 750W | 2,000–3,000W |
| Refrigerator | 150–200W | 800–1,200W |
| Electric water heater | 4,000–5,500W | 4,000–5,500W |
| Pool pump (1 HP) | 1,000W | 2,500–3,500W |
| Clothes dryer (electric) | 5,000W | 5,000W |
| EV charger (Level 2) | 7,200W | 7,200W |
Why Texas Homes Need Bigger Generators Than Most Guides Suggest
Most generator sizing guides are written for northern climates where heating is the main concern. In Texas, air conditioning is the dominant electrical load — and AC units have extremely high starting wattages. A generator sized "just right" for a northern home is often undersized for a Texas home running AC in 100°F+ summer heat. We always recommend sizing up by at least one tier when installing in Central Texas.
Natural Gas vs. Propane — Which Is Right for Your Texas Home?
Natural Gas Generators
Natural gas is the preferred fuel for Austin and suburban Hill Country homes with gas service. The generator connects directly to your gas line and can run indefinitely during an outage — there's no tank to fill, no fuel to store, and no worry about running out during an extended ERCOT event. Most of Austin's residential areas have natural gas service through Atmos Energy.
Propane Generators
Propane is the right choice for rural Dripping Springs, Wimberley, and other Hill Country properties without natural gas service. A 500-gallon propane tank provides approximately 5–7 days of continuous operation at 50% load for a 22 kW generator. Many rural homeowners already have propane tanks for cooking or heating — adding generator capacity to an existing tank is often straightforward.
Automatic Transfer Switch — Why It Matters
A standby generator without an automatic transfer switch (ATS) requires you to manually start the generator and connect it to your home — which means going outside during a storm, in the dark, potentially with no idea when the power went out. An automatic transfer switch detects the outage and starts the generator within 10–30 seconds, without any action from you. Every whole-home generator installation we do includes an ATS.
Do I Need a Panel Upgrade for a Generator?
Not always — but often yes. If your home has a 100A panel, upgrading to 200A before installing a generator is strongly recommended. A 22 kW generator feeding power into a 100A panel is like running a fire hose through a garden hose. We assess your panel during the free generator consultation and include panel upgrade recommendations in the quote if needed. Many homeowners combine both projects for maximum efficiency and savings.
How Much Does a Whole-Home Generator Cost in Austin?
Installed generator costs in Austin in 2026 typically range from $5,000 to $15,000+ depending on generator size and installation complexity. A 22 kW Generac or Kohler unit — the most common size for Austin homes — typically runs $8,000–$12,000 fully installed including the automatic transfer switch, concrete pad, and all electrical work. We provide free in-home consultations with detailed, no-obligation quotes.
Frequently Asked Questions
What size generator do I need for a 2,000 square foot house in Texas?
A 2,000 square foot home in Texas typically needs a 16 to 22 kW standby generator to power essential systems including HVAC, refrigerator, lights, outlets, and a well pump if applicable. A 22 kW generator provides comfortable whole-home coverage for most homes this size.
What size generator do I need to run my air conditioner in Texas?
Running a central air conditioner in Texas requires a generator sized for the AC unit's starting load, which can be 2 to 3 times the running wattage. A 3-ton AC unit typical for a 1,500 to 2,000 sq ft home needs at least a 14 to 17 kW generator to run reliably alongside other household loads.
Is a 22 kW generator enough for a whole house?
A 22 kW generator is sufficient for most Texas homes under 3,500 square feet with a single HVAC system. It will power your air conditioning, refrigerator, lights, outlets, and most appliances simultaneously. Larger homes with multiple HVAC systems, pools, or EV chargers may need 24 kW or larger.
How much does a whole-home generator cost in Austin Texas?
A whole-home standby generator in Austin typically costs between $5,000 and $15,000 installed. A 22 kW Generac or Kohler generator installed by a licensed electrician typically runs $8,000 to $12,000 in the Austin market, including the automatic transfer switch and all electrical work.
Should I get a natural gas or propane generator in Texas?
Natural gas generators are preferred in Austin and surrounding areas with gas service because they connect directly to the gas line and can run indefinitely. Propane is the better option for rural Hill Country properties without natural gas service — a 500-gallon tank provides approximately 5 to 7 days of continuous power at 50% load.
Not Sure What Size Generator You Need?
We perform a free in-home load calculation and give you an honest recommendation.
No pressure, no upselling — just the right generator for your home.