what size home generator do i need
For most homes, the right generator size depends less on square footage and more on what you want to run: essentials only, key comforts, or the whole house. As a rough guide, essentials often need about 2,000 to 4,500 watts, a small-to-medium home commonly lands around 5,000 to 10,000 watts, and whole- house standby setups often start around 15 kW to 22 kW or more.
Quick scoop
If you only want to keep the fridge, a few lights, and chargers going, a smaller portable generator may be enough. If you want to run central air, electric heat, or multiple large appliances at once, you’ll likely need a larger standby unit and a professional load calculation.
Practical sizing guide
| What you want to power | Typical size |
|---|---|
| Essentials only | 2,000–4,500 watts |
| Small to medium home | 5,000–10,000 watts |
| Mid-size home with more loads | 15,000–20,000 watts |
| Whole-house with HVAC | 15 kW–22 kW+ standby |
Best way to choose
- List the appliances you truly need during an outage.
- Add up their running watts.
- Add the highest starting watt surge for motors like refrigerators, sump pumps, or A/C.
- Choose a generator with headroom above that total.
Rule of thumb
If you’re unsure, go one size up from your estimate, especially if you have well pumps, central A/C, or electric heating. Undersizing can overload the generator and shorten equipment life.
If you want, I can help you size one exactly if you tell me your home size and the appliances you want to run.