What can a 4,000 watt generator run?

These loads fit under 4,000 watts in WattSizer's conservative default model. Treat this as a screening list, then verify real nameplates and starting amps.

ScenarioRunningStartingRecommended
What size generator for a refrigerator and freezer?460 W1,480 W1,800 W
What size generator for a sump pump and refrigerator?1,330 W2,480 W3,000 W
What size generator for a furnace and refrigerator?1,005 W2,025 W2,500 W
Portable power station size for CPAP overnight85 W85 W200 W
Portable power station for CPAP with humidifier overnight130 W160 W200 W
Apartment outage generator alternatives for fridge, router, and lights265 W765 W1,000 W
What size generator for garage freezer and sump pump?1,300 W2,450 W3,000 W
Backup power size for oxygen concentrator and phone590 W740 W900 W
What size generator for window AC and refrigerator?1,380 W3,080 W3,700 W
Will a 1000 watt generator run refrigerator, freezer, and lights?460 W1,480 W1,800 W
Will a 1000 watt generator run refrigerator, sump pump, and router?1,255 W2,405 W2,900 W
Will a 1000 watt generator run refrigerator, furnace blower, and lights?980 W2,000 W2,400 W
Will a 1000 watt generator run freezer and well pump?1,280 W2,780 W3,400 W
Will a 1000 watt generator run window AC, refrigerator, and router?1,305 W3,005 W3,700 W
Will a 1000 watt generator run sump pump, dehumidifier, and freezer?1,800 W2,950 W3,600 W
Will a 1000 watt generator run garage door opener, sump pump, and lights?1,500 W2,700 W3,300 W
Will a 1000 watt generator run refrigerator, TV, router, and laptop?415 W1,435 W1,800 W
Will a 1500 watt generator run refrigerator, freezer, and lights?460 W1,480 W1,800 W
Will a 1500 watt generator run refrigerator, sump pump, and router?1,255 W2,405 W2,900 W
Will a 1500 watt generator run refrigerator, furnace blower, and lights?980 W2,000 W2,400 W
Will a 1500 watt generator run freezer and well pump?1,280 W2,780 W3,400 W
Will a 1500 watt generator run window AC, refrigerator, and router?1,305 W3,005 W3,700 W
Will a 1500 watt generator run sump pump, dehumidifier, and freezer?1,800 W2,950 W3,600 W
Will a 1500 watt generator run garage door opener, sump pump, and lights?1,500 W2,700 W3,300 W
Will a 1500 watt generator run refrigerator, TV, router, and laptop?415 W1,435 W1,800 W
Will a 2000 watt generator run refrigerator, freezer, and lights?460 W1,480 W1,800 W
Will a 2000 watt generator run refrigerator, sump pump, and router?1,255 W2,405 W2,900 W
Will a 2000 watt generator run refrigerator, furnace blower, and lights?980 W2,000 W2,400 W
Will a 2000 watt generator run freezer and well pump?1,280 W2,780 W3,400 W
Will a 2000 watt generator run window AC, refrigerator, and router?1,305 W3,005 W3,700 W
Will a 2000 watt generator run sump pump, dehumidifier, and freezer?1,800 W2,950 W3,600 W
Will a 2000 watt generator run garage door opener, sump pump, and lights?1,500 W2,700 W3,300 W
Will a 2000 watt generator run refrigerator, TV, router, and laptop?415 W1,435 W1,800 W
Will a 2500 watt generator run refrigerator, freezer, and lights?460 W1,480 W1,800 W
Will a 2500 watt generator run refrigerator, sump pump, and router?1,255 W2,405 W2,900 W
Will a 2500 watt generator run refrigerator, furnace blower, and lights?980 W2,000 W2,400 W
Will a 2500 watt generator run freezer and well pump?1,280 W2,780 W3,400 W
Will a 2500 watt generator run window AC, refrigerator, and router?1,305 W3,005 W3,700 W
Will a 2500 watt generator run sump pump, dehumidifier, and freezer?1,800 W2,950 W3,600 W
Will a 2500 watt generator run garage door opener, sump pump, and lights?1,500 W2,700 W3,300 W

Never operate a fuel-burning generator indoors, in a garage, on a porch, or near open windows. Use a listed transfer switch or interlock installed by a qualified electrician for home wiring, and verify actual device nameplates before buying equipment.