What Can a Generator Run?
A practical overview of what generators can power, how wattage affects appliance use, and which generator sizes make sense for different situations.
Quick answer
2,000–3,000W covers essentials, fridge, lights, a few outlets, phone charging. 5,000–7,500W adds a window AC, sump pump, or well pump. 10,000W+ handles most of a home short of central AC and electric water heating. Leave about 20% headroom for startup surges.
Typical appliance wattage
- Refrigerator: about 100–800W running, often higher at startup
- Microwave: about 800–1200W
- LED lights: about 10–20W each
- TV: about 100–300W
- Space heater: about 1500W
- Well pump or sump pump: often requires a large startup surge
Real power needs vary by appliance size, age, and motor load.
Generator size quick overview
These guides break down what common generator sizes can realistically power.
Popular generator example
If you want to see a real-world portable inverter example, start here:
What matters most when choosing a generator
- Running watts: the continuous power the generator can provide
- Starting watts: extra power needed when motors first start
- Total combined load: what all your active devices add up to
- Safety margin: it is smart to leave unused capacity instead of pushing the generator to its maximum
A generator may technically run a load on paper, but real-world startup surge and load changes can still cause problems if you cut it too close.
Simple rule of thumb
Try to stay below about 80% of rated capacity for more reliable operation, better efficiency, and extra room for startup surge.
Find your exact size
The easiest way to know what your generator can run is to estimate the actual appliances you want to power.
Plan runtime and fuel
Once you know what your generator can run, the next step is figuring out how long it will run and how much fuel you should store.
Explore more
See all related content in the Power & Generators Guides.
Simple takeaway
A generator can run anything from a few essentials to much of a home, depending on its wattage and the loads you place on it. The best approach is to start with your actual appliances, choose the right size, and then plan your fuel and runtime around that setup.