A portable generator can keep your home running during power outages, but choosing the wrong size can leave you without enough power — or cost you more than necessary.
If you’re shopping for a portable generator for home backup, this guide explains what size generator you actually need, what appliances you can run, and when a portable unit makes sense compared to standby options.
WHAT CAN A PORTABLE GENERATOR POWER?
Most portable generators can run:
- Refrigerator
- Sump pump
- Furnace fan
- Lights
- Wi-Fi router
- Small window AC (larger units)
Heavy loads like central AC or electric dryers usually require larger systems.
HOW TO CHOOSE THE RIGHT GENERATOR SIZE
Small Homes / Essentials Only (3,000–4,000 watts)
- Refrigerator
- Lights
- Router
- Phone chargers
Medium Homes (5,000–7,500 watts)
- Fridge
- Sump pump
- Furnace fan
- Freezer
- TV
Large Homes / High Demand (8,000–10,000+ watts)
- Multiple appliances
- Larger pumps
- Limited HVAC use
Always check starting watts, not just running watts.
GAS VS INVERTER GENERATORS
Gas Generators
- Higher output
- Lower upfront cost
- Louder
Inverter Generators
- Quieter
- More fuel efficient
- Cleaner power (better for electronics)
SAFETY CONSIDERATIONS
- Never run indoors or in garages
- Use heavy-duty extension cords
- Consider a transfer switch for safer operation
FINAL VERDICT
For most homes, a 5,000–7,500 watt portable generator offers the best balance of power and price.
If you only need essential backup and quieter operation, an inverter generator may be worth the investment.
Homes with basements should also consider a sump pump backup system to protect against flooding during outages.