What will a 5,000-watt generator run?
A 5,000-watt portable covers a refrigerator, a 1 HP well pump, the furnace fan, and the storm basics at once (about 5,700W peak), with headroom for a window AC. It will not run central AC, an electric water heater, or an electric dryer: those are 240V loads that need a bigger class or a home standby unit. This is the size most people mean by "a generator for the house" during an outage.
The three tables sort common outage load lists by how a 5,000-watt handles each one. Every running and starting figure comes from the same engine the wattage picker and the wattage chart use. "Runs easily" means the list stays under 80% continuous with the start spike covered; "runs with load management" means it fits but you're near the ceiling or staggering starts; "won't run" means the running total or the start spike is over the line. Loads tagged 240V also need a 240V outlet, which starts at the 5,000W class.
Runs easily
| Load list | Running | Peak start |
|---|---|---|
| Lights, Wi-Fi, and phone or laptop chargers | 200 W | 200 W |
| TV, streaming box, Wi-Fi, and lights | 400 W | 400 W |
| A CPAP machine overnight | 60 W | 60 W |
| One 1,500W space heater | 1,500 W | 1,500 W |
| A microwave on its own | 1,400 W | 1,400 W |
| A refrigerator on its own | 700 W | 2,200 W |
| Fridge, freezer, and the keep-alive basics | 1,400 W | 2,900 W |
| Winter storm: fridge, furnace blower, lights, Wi-Fi | 1,700 W | 3,250 W |
| Flooding storm: fridge, furnace, 1/2 HP sump, basics | 2,750 W | 4,300 W |
| Well water: fridge, 1/2 HP well pump, basics | 1,900 W | 3,400 W |
| A 10,000 BTU window AC with fridge and basics | 2,100 W | 3,600 W |
| Kitchen morning: microwave, coffee maker, fridge | 3,100 W | 4,600 W |
| A 1 HP well pump with fridge and furnace 240V | 3,700 W | 5,700 W |
Won't run on this size
| Load list | Running | Peak start |
|---|---|---|
| An electric water heater with fridge and basics 240V | 5,400 W | 6,900 W |
| Central AC (3 ton) with fridge and furnace fan 240V | 5,200 W | 7,700 W |
| An electric dryer 240V | 5,400 W | 6,750 W |
| Level 2 EV charging (40A) 240V | 9,600 W | 9,600 W |
| Central AC, electric dryer, fridge, and furnace together 240V | 10,600 W | 13,100 W |
| Central AC, dryer, and Level 2 EV all at once 240V | 20,000 W | 22,500 W |
How to read these tables for your own list
A 5,000-watt holds about 4,000 watts continuously (80% of its 5,000W rating) and survives a start spike up to 6,250W. Add the running watts of everything you'll have on at once, then add the single largest start surge on top of that total. If both numbers fit, so does the list. The wattage picker does that arithmetic for your exact appliances, and the wattage chart lists the per-appliance numbers behind these lists.
Anything that connects to your electrical panel (a furnace, well pump, central AC, or a whole-house transfer) is licensed-electrician work, wired through a transfer switch or interlock. A generator powers those through that equipment, never by backfeeding an outlet, and it always runs outside, well away from the house.
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Questions people ask
Will a 5,000-watt generator run central air conditioning?
No. A 3-ton central AC compressor runs about 3,500W and its bare start is far past a 5,000W unit's 6,250W peak, and it is a 240V load besides. A 5,000W portable is sized for the storm-basics list plus a window AC or a well pump, not central air. Central AC backup is home-standby work.
Will a 5,000-watt generator run a well pump?
A 1 HP well pump (2,000 running, 4,000 starting) fits, and so does the fridge and furnace beside it. The catch is the outlet, not the watts: well pumps are 240V, so you need a generator with a 240V receptacle (the 5,000W class is where those start) and an electrician-wired inlet, because the pump is hardwired.
How many appliances can a generator run at once?
As many as fit two limits at the same time: the running watts have to stay under about 80% of the rating (that is the 5,000W a 5,000-watt holds continuously, so roughly 4,000W of steady load), and the single biggest motor start has to land under the 6,250W peak. Add running watts for everything on, then add the largest one start spike on top. The tables above do that for the common lists.
Running watts or starting watts: which one sizes the generator?
Both, on different clocks. Running watts are what the generator holds for hours, so they set the continuous size; the starting spike is what it has to survive for about a second when the biggest motor kicks in. A unit that clears the running total but not the spike stalls at start; one that clears the spike but runs at 95% all night runs hot and drinks fuel.