What size generator for a 4,000 sq ft house?
A 4,000 square foot home's backup needs depend on how much you want to keep running. Here are surge-accounted estimates for three coverage levels.
| Coverage | Running | Peak surge | Recommended |
|---|---|---|---|
| Essentials only | 10,000W | 13,000W | 16,000W |
| Essentials + comfort | 16,000W | 21,600W | 26,000W |
| Whole home | 28,000W | 39,200W | 47,500W |
Square-footage estimates are a rough planning guide; central AC, electric heat, and well pumps move these numbers significantly. Itemize for accuracy.
Get an exact number
Square footage can't see your specific appliances. Use the load sizer to pick exactly what you'll run and get a surge-accurate recommendation:
Common questions
What size generator runs a 4,000 sq ft house?
For whole-home coverage including central AC, a 4,000 sq ft home typically needs around a 47,500W (48kW) class generator. For essentials only, far less — see the table above.
Does square footage alone decide generator size?
No. Square footage is only a rough proxy. Your actual need depends on specific appliances — especially central AC, electric heat, and well pumps. Itemize your loads for an accurate figure.