Generator Sizing Calculator
Determine the right generator size for your home by selecting the appliances you want to power during an outage. Our calculator will recommend the appropriate generator size based on your specific needs.
Select Your Appliances
Your Selected Appliances
No appliances selected yet. Add appliances from the left panel to see your power needs.
Tips for Accurate Sizing
Consider Start-Up Power Requirements
Appliances with motors (refrigerators, AC units, pumps) need 2-3 times more power to start than to run continuously.
Identify Essential vs. Non-Essential Items
Mark appliances you absolutely must run during an outage. This helps if you need to prioritize or plan for a smaller generator.
Allow for Future Growth
When possible, choose a slightly larger generator to accommodate future appliances or home expansions.
Load Management Systems
Consider using load management systems that automatically prioritize essential items and cycle non-essential ones. This can let you use a smaller generator for a larger home.
Ready for the Next Step?
Get a personalized quote from qualified generator dealers in your area.
Frequently Asked Questions
Why is proper generator sizing important?
An undersized generator won't power all your needs and may fail from overload. An oversized generator costs more to purchase and operate while running inefficiently. Proper sizing ensures reliability, efficiency, and value.
What's the difference between running watts and starting watts?
Running watts (or rated watts) is the continuous power an appliance needs to operate. Starting watts (or surge watts) is the extra power needed for a few seconds when motor-driven appliances first start up. Generators must handle both requirements.
Do I need to run everything during a power outage?
No, and many homeowners choose not to. By identifying essential appliances (refrigerator, heating, basic lighting) versus non-essential ones (clothes dryer, dishwasher), you can select a more affordable generator that handles your critical needs.
What if I can't find my appliance's wattage?
Look for an identification plate or sticker on the appliance that shows watts, amps, or volts. If it only shows amps and volts, multiply them together (Watts = Volts × Amps). For 120V appliances, amps × 120 = watts. For 240V appliances, amps × 240 = watts.
Can I install a generator myself to save money?
Home standby generator installation requires professional electricians and often plumbers for gas connections. Improper installation can be dangerous and may void warranties. Additionally, permits and inspections are typically required. We recommend professional installation for safety and compliance.
