Pre-filled with typical essential-circuit loads for a 3,000 sq ft home — adjust any field to match your actual appliances.
This estimate covers typical essential circuits for at 3,000 sq ft, many households want more than bare essentials covered — some kitchen circuits, additional lighting zones, and a larger central AC system are common additions. Add up your specific appliances in the generator backup calculator for a precise figure rather than relying on square footage alone.
Square footage is a rough proxy for how many essential circuits a home typically has, not a precise sizing method — two homes of the same size can need very different generator capacity depending on whether they have a well pump, central air, or a second refrigerator. Use this as a starting estimate, then confirm against your actual appliance list with the full generator backup calculator and check individual high-surge items like well pumps or AC compressors against the surge watts calculator.
Once you've settled on a generator size, size the fuel supply to match with the fuel consumption calculator or the propane tank size calculator depending on fuel type.
Treat it as a starting point — at 3,000 sq ft, many households want more than bare essentials covered — some kitchen circuits, additional lighting zones, and a larger central AC system are common additions. Confirming your specific appliance list against the full generator backup calculator avoids both undersizing (appliances that won't start) and overpaying for unused capacity.
Surge watts almost always determines the minimum generator size needed, since motor-driven appliances like AC compressors, well pumps, and refrigerators briefly draw several times their running wattage at startup — running watts only matters once surge capacity is already covered.