Tips for Choosing the Right Size Generator for Your Home

Investing in a backup power source is one of the smartest decisions a Portland homeowner can make, especially when winter storms threaten the grid. However, buying a unit that is too small leaves you in the dark, while buying one that is too big wastes money on fuel and initial costs. Finding the “Goldilocks” size for your home requires you to carefully calculate your household’s energy needs.

Below are some tips for choosing the right size generator for your home so you can maintain power you can trust.

Calculate Your Power Requirements

The first step is to create a list of every appliance you need to power during an outage. Distinguish between essential items (for example, the fridge, furnace, and medical equipment) and luxury items (such as the television and dishwasher).

Check the label on each appliance to find its running watts and starting watts. Starting watts are important because appliances with motors, such as air conditioners or sump pumps, require a surge of extra power to turn on. Add up the running watts of all items you want to power simultaneously, then add the highest single starting watt figure to that total. This number gives you a baseline for the generator capacity you need.

Determine Your Fuel Source

Standby generators typically connect directly to your home’s natural gas or liquid propane supply. This allows for automatic restoration of power without manual refueling. Portable generators usually run on gasoline and require you to store fuel safely.

If you choose a standby model, ensure your existing gas meter or propane tank can support the additional load. A professional installer can assess your fuel pressure and volume to confirm compatibility before installation begins.

Consider Future Electrical Needs

Thinking ahead will save headaches. If you plan to add a central air conditioning unit, a hot tub, or an electric vehicle charger in the next few years, factor those loads into your calculation now. Upsizing slightly today prevents having to replace your entire unit shortly after installation.

Consult a Licensed Professional

While online calculators provide rough estimates, they cannot replace the accuracy of an on-site load calculation. A licensed electrician or generator specialist will inspect your electrical panel, identify potential code issues, and recommend a unit that fits your infrastructure.



Proper sizing also protects the longevity of the unit. An undersized generator runs at full capacity constantly, which can cause overheating and premature failure. You’ll likely end up needing a home generator repair much sooner than expected.

Following these tips for choosing the right size generator for your home will keep your family safe and comfortable through the worst Pacific Northwest weather. Ready to secure your home’s power? Contact NW Generator Pros today for a free estimate and expert sizing consultation.