How many watts does it take to run a house?
Short answer: The average US home uses about 899 kWh a month (EIA), which is an average draw of about 1,250 watts around the clock. Peaks are much higher: 5,000–10,000 W when the AC, the dryer and the oven overlap. To run the essentials in an outage you need about 5,000–7,500 W of generator; to run everything, including central air, 15–25 kW.
Average watts vs peak watts
Energy and power are different questions. Your bill counts energy in kWh: 899 kWh a month for the average US residential customer (EIA, 2022). Spread over a 30-day month, that is an average of 1,249 W. But you never use power evenly. At 3 a.m. the house may draw 200–400 W (fridge, router, standby loads); at 6 p.m. in July, with the AC, oven and dryer running, it can pull 8,000–12,000 W for a while.
Generators, batteries and your electrical service are sized for the peak, plus the extra surge when motors start. Your solar array and your bill are sized by the energy.
Watts to run the essentials in an outage
Refrigerator, ½ hp sump pump, gas furnace blower, LED lights, internet, phone charging and a microwave, computed with our generator calculator:
| Load set | Running W | Peak with one motor starting | Smallest common generator |
|---|---|---|---|
| Essentials | 3,275 | 4,825 | 7,500 W portable |
| Essentials + 3-ton central AC | 6,775 | 14,275 | 18 kW standby |
Watts to run the whole house
Whole-house backup means covering every large load that might run together. A rough rule from whole-house generator sizing: homes with gas heat and no central air land around 10–14 kW; with central air, 18–22 kW; all-electric homes with an electric furnace or resistance heat, 24 kW and up. An electrician's load calculation (NEC 220.82 for existing homes) gives the real number.
What your electrical service can deliver
| Service | Maximum watts at 240 V | 80% continuous |
|---|---|---|
| 100 A | 24,000 | 19,200 |
| 150 A | 36,000 | 28,800 |
| 200 A | 48,000 | 38,400 |
Most homes never come close to their service rating; it is sized for the worst case. Adding an EV charger or a heat pump is where load calculations matter.
What it costs
899 kWh at the US average price of 18.19¢/kWh (EIA, January–July 2026) is about $163.53 a month. Price your own usage with the electricity bill calculator, or see how many solar panels would cover it.
Add up the watts for your house