Best Portable Generator for Home Backup in 2026

Essentials run on 3,500 to 5,000 W. A fridge at 150 W, a furnace blower at 600 W, 200 W of lights and internet and an 800 W sump pump total 1,750 W. Times 1.2 that is 2,100 W running. The sump pump adds about 1,200 W when it starts, so peak is 2,950 W, and times 1.1 is about 3,250 W starting. A 4,500 W class inverter clears it, and the 5,000 W class leaves room for a microwave.

A well pump or window AC moves you to 7,000 to 9,500 W. Add a 1/2 HP 240V well pump (1,000 W running, about 3,000 W starting) and a 10,000 BTU window unit at about 900 W, and you are at 3,650 W running. That works out to about 4,400 W running and 6,200 W starting after margins, and the pump needs 240V. Only generators with an L14-30R or 14-50R outlet feeding an interlock or transfer switch can power it.

Near-whole-home means 12,000 W starting and up. Put a 4,500 W electric water heater on top of the tier above and running climbs to about 9,800 W, with starting near 11,200 W. That is the 10,500 to 12,000 W running class. Central air is the load that breaks most plans, so put your AC's nameplate numbers into the generator sizer before you pick this tier.

Buy an inverter here. They run at 52 to 61 dBA instead of 72 or more, and they throttle down at light load, so a tank lasts most of a day.

These run on cords. Set the generator 20 ft out, run a 12-gauge cord to the fridge and a fan cord to the rest. None of them has a 240V outlet, so a well pump or anything hardwired is out of reach.

This is the tier most houses on a well should buy. You need a 240V twist-lock or 50 A outlet and a hookup to the panel, and the generator should make at least 6,000 W running so the pump can start with the fridge and furnace already on.

Inverter or open frame is a noise and fuel call. The iGen8200TFc and Champion 8500 are inverters at 60 to 61 dBA. The Westinghouse WGen7500DFc and WGen9500DF are open-frame units at 72 to 74 dBA that cost less and burn more fuel. Neighbors hear the difference all night.

Buy tri-fuel at this size if you have a gas meter. These engines burn about a gallon an hour at half load, and natural gas ends the fuel runs entirely. On natural gas the output drops, so check the natural gas number against your load, not the gasoline one.

A 30 A L14-30 hookup tops out at 7,200 W. To use 10,000 W or more in the house, your electrician fits a 50 A inlet and you run a 14-50 cord. Budget for that in the install quote.

Gasoline gives full power and is easy to buy before a storm. Fuel use comes straight from the spec sheets, tank size divided by run time. The iGen5000DFc burns about 0.19 gallons an hour at quarter load. The WGen7500DFc burns about 0.6. The DuroMax XP13000HXT burns about 0.98 at half load, and the Champion 201161 about 1.22.

Run that for 24 hours at an assumed $3.50 a gallon. The iGen5000DFc uses about 4.5 gallons, around $16 a day. The WGen7500DFc uses about 14.4 gallons, around $50 a day. The XP13000HXT at half load uses about 23.4 gallons, around $82 a day. A three-day outage on the WGen7500DFc means storing about 43 gallons, and untreated gas goes stale in months.

Propane stores for years and costs you about 10 percent of rated power. It also holds roughly 25 percent less energy per gallon, so you burn more of it. A 20 lb tank holds about 4.6 gallons and runs the iGen5000DFc about 18 hours at quarter load. On a 7,500 W open-frame unit it lasts closer to 6 hours, so big generators want 100 lb cylinders.

Natural gas is the cheapest and never runs out. A gallon of gasoline holds about 1.2 therms, so at an assumed $1.50 a therm the same run costs about half as much. You give up more power, 17 to 20 percent on these tri-fuel units, and a plumber has to add a quick-connect at the meter.

An interlock kit is the cheapest way to power the panel. It is a plate that keeps the main breaker and the generator breaker from being on together, so you choose any circuit you want. The kit, inlet box and cord below are the parts you buy before the electrician. A 10-circuit transfer switch costs more and limits you to the circuits it is wired to, but it is the simpler setup for some panels.

Either way, a licensed electrician installs it. Never backfeed through a dryer outlet or any wall outlet with a double-ended cord. That puts generator voltage on the utility line and can kill a line worker.

Run the generator outdoors, 20 ft or more from windows and doors, exhaust pointed away. Never in a garage, even with the door open. Put a battery CO alarm on every sleeping level before the first start.