What Can a 4000 Watt Generator Run? TOP 3 4000 Watt Generators

In this guide, we will cover what can a 4000 watt generator run, the top 3 best 4000-watt generators, the most searched questions about this, and helpful tips.

Due to the growing number of natural disasters and power outages, the sales volume of portable generators has exponentially increased.

A 4000-watt generator is the most popular choice for backup power, camping, and RV because it is not too big, and not too small in terms of size and power. (check out our buying guide about the portable Rv generators)

Usually, a 4000-watt generator approximately provides 33.4 amps for 120v and 16.7 amps for 240v. In simple terms, it should run the following appliances:

Ac unit small – 1000 to 1200 watts
Fridge with a freezer – 600 to 700 watts
Well pump small – ½ HP 1000 watts
Washing machine – 1150 to 1200 watts
Microwave oven – 800 to 1000 watts
Pressure cooker – 700 to 800 watts
Standard dishwasher – 1300 to 1500 watts
Toaster – 700 to 850 watts
Ceiling fan – 40 to 60 watts
Heating system small – 500 to 600 watts
Power tools (a couple of small power tools) – 800 to 1000 watts
Hammer drill – 800 to 1000 watts
Bench grinder – 1300 to 1400 watts
Electric water heater – 3500 to 4000 watts
Steam iron – 1800 to 2200 watts

Above mentioned appliances and their wattage levels are a rough estimation. Before we break it down, you would need to understand peak/surge watts, and running watts.

What are Starting Watts and Running Watts?

Starting/peak watts: The surge of maximum power the generator can provide for a few seconds to start motor-driven appliances.

Motor-driven appliances need a few extra watts from their original capacity to overcome inertia and start. Later, these appliances settle down to their rated capacity.

Rated/running watts: The amount of power the generator can provide constantly for hours. Rated or running watts are always less than the starting watts. Not all appliances need an initial push to start.

Before purchasing a generator, check its starting and running watts, then calculate starting and running watts of appliances you need to run.

Sometimes people purchase 4000-watt generators without even knowing the rated and surge watts of devices they need to start and they later complain about the generator.

Recommended Read: What Will A 12000 Watt Generator Run

What Can A 4000 Watt Generator Run?

A 4000-watt generator provides enough power to run the following appliances:

Appliance	Quantity	Peak watts	Running watts
A standard fridge	1	1200	200
Microwave oven	1	1000	1000
Coffee maker	1	600	600
AC (10,000) BTU	1	4400	3000
Electric blanket	1	200	200
Computer	1	250	250
Incandescent lights	5	300	300
Sump Pump	1	800	1500 to 300
Well pump	1	1000	2000

Suppose a generator is rated at 3800 watts, and 4000 peak watts. If you need to run 4 appliances together whose running watts collectively are 3600 watts, and 3900 starting watts, so in theory, your generator should provide enough power to run all four appliances at once.

But, you shouldn’t push it to its peak because not all generators provide as much power as they advertised. So be careful.

Checkout our guide about what can a 3500 watt generator run?

Can A 4000-Watt Generator Run A Central Air Conditioner?

Yes. It can surely run a central AC system of 10,000 BTU.

AC UNIT	Peak watts	Running watts
10,000 BTU	2200	1500

Will A 4000 Watt Generator Run Space Heaters?

Absolutely. Normal space heaters take 1750 to 1800 running watts, and 1800 starting watts. You can easily run 2 space heaters if you want. Nowadays, there are even more efficient space heaters in the market.

Will A 4000-Watt Generator Run A Microwave, Fridge?

It should easily run both without any problem. A standard microwave takes about 1000 running watts, a fridge takes 1200 to 1000 surge watts, and 200 running watts (check out our guide about is it safe to run a refrigerator on a generator?). Run some other low-wattage appliances with these two at a time as well.

Can A 4000 Watt Generator Run A Circular Saw?

YES. A circular saw takes about 1400 running watts, and 2300 starting watts. It will run two circular saws at once if they are energy efficient.

What Will A 4000-Watt Generator Run For A Work Site?

Below is an estimated power requirement of various tools on a site. Calculate the surge and running watts of each appliance, then compare it with your generator.

Mostly, 10000-watt generators are preferred for work sites, but a 4000 should do the job if there is no other option available.

Checkout our guide about best 5000 watt generators?

Appliance	Running watts	Surge watts
Circular saw	1400	2300
Electric drill	600 watts	600 watts
Portable air compressor ½ HP	1000	1600
Chainsaw	1500	1500
Bench grinder	1400	2500

How To Safely Run A 4000-Watt Generator?

Before refueling, turn off the generator. Let it cool for a couple of minutes.
Don’t plug the generator in a wall outlet if you don’t know how to do it. Only licensed electricians should plug the generator into a main electrical panel or wall outlet.
Plug your equipment directly into the generator using a heavy-duty outdoor extension cord that handles high loads if your generator is not plugged into the main electrical panel.
Operate your generator in a dry place where plenty of ventilation is available.
Don’t sit near the generator. They release CO (carbon monoxide) which is an odorless poisonous gas. If proper ventilation is not available, CO can be accumulated in one place and can harm you in a bad way.
Change the oil and spark plug when it is due. Don’t be clumsy. Using the same oil for a longer period can cause internal friction and potential damage.

Alex Black

Alex Black is a seasoned electrical engineer with a remarkable 8-year track record specializing in appliances, generators, and transfer switches. With extensive hands-on experience in the field, Alex possesses a deep understanding of electrical systems and their intricate workings. Throughout their career, Alex has consistently demonstrated expertise in designing, troubleshooting, and maintaining various electrical appliances.