Add up your essential appliances' wattage to find the right size backup generator for your home.
Sizing a generator means adding up the running wattage of everything you want powered at once, then leaving buffer room for the extra surge wattage motors need to start up.
Suggested Generator Size = Total Running Watts × 1.3 (a 30% buffer for startup surges)
A refrigerator (700W) and sump pump (800W) total 1,500W running, suggesting at least a 1,950W generator to handle startup surges safely.
It sums the running wattage of all devices/appliances you want powered simultaneously, plus accounts for the higher starting (surge) wattage some motors need.
Motor-driven appliances (like refrigerators and air conditioners) draw a brief surge of power well above their running wattage when first starting up.
No — it's wise to add a safety margin above your calculated total to avoid overloading the generator and to allow for adding devices later.