2024 Update : What's the Best 4000 Watt Generator? Reviews

Hybrid open frame inverter. Good buy. (Amazon)

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In 2023, as we all try to endure this global pandemic, we’ve all realized that we need to prepare for anything. People have become more willing to prepare for anything. A generator will give you peace of mind for when the power goes out, and eventually it will. In this article, we answer your question of : What’s the Best 4000 Watt Generator worth spending your money on?

Westinghouse is always a worthwhile brand to consider. They’ve been in business since 1886. They know how to make generators. I am a fan of their product line because of their long history, and because their generators offer a good balance of features, quality and overall value for the money. They’re a consumer brand, meaning, they actually make great products and charge you a fair price. Crazy, I know. Just look at their customer satisfaction reviews and decide for yourself.

Table of Contents...

0.1 — More Wattage is Better

1 Intro | Best 4000 Watt Generator?

— More Wattage is Better

I find it interesting that people are very specific when they shop for generators. Pick a generator size and I guarantee that, every month, thousands of people are researching for that specific size generator. So, why buy a 4000 watt generator? I mean why so specific? Did you calculate all of your power needs down to the single wattage? If you think you need 4000W, you probably need a little more. Generators are a good example of buying a little more power than you need, like pool pumps.

Why? Well, you’d rather not be running the generator at full speed, for a few reasons. First, it will be running at its loudest non-stop, which is fine if you buy an inverter generator like the 4500W Westinghouse, but traditional gas generators can be loud. Well, who am I kidding — they are loud.

And second, it will likely last longer if your running it below the maximum, making if far more efficient, putting less stress on its components.

— and which models are worth your money? We review several excellent 4500W portable generators.

Intro | Best 4000 Watt Generator?

If you’re looking for a generator that will serve you well as a portable power supply for your RV and give you enough electricity to supply you with a reasonable amount of backup power for your home, a 4000 watt generator could be your best bet. Even though 4000 watts isn’t quite enough to supply your entire house, it will keep more than just the bare essentials powered up.

What makes this size generator so great is that they are reasonably lightweight and are, therefore, more portable than a really large generator. They are also more fuel efficient than larger machines and cheaper to buy. I should justify this by saying that larger generators can often be more efficient, in that they may provide more kilowatt-hours per gallon of gas. Though, because you’re not able to use as many kilowatts with a smaller generator, you will obviously be burning through less gas.

Westinghouse iGen4500 | Powerful Compact Inverter Generator

Ultra-quiet and produces clean power. Excellent buy!

Buy on Amazon

►Read our comprehensive review of the Westinghouse iGEN4500.

Note from Editor : This 4500W Westinghouse is an inverter generator which means it can safely run all of your sensitive electronics and tools. Traditional gas generators do not produce clean energy. You need to choose the right model depending on what you intend to use the generator for. Ultimately, what do you plan on running? Use a generator calculator to ensure you buy the right size portable generator.

To say which is the best 4000 watt generator is isn’t an easy call. A quality generator isn’t cheap and one has to consider your purchase price along with your running costs. In my opinion, Honda generators are usually the best. But they’re really pricey and are, therefore, not the best choice for most domestic users. An industrial-grade 4000W generator is probably the best option for daily use like off-grid homes, and farmers or contractors who use their generators on a daily basis.

If you’re looking for a home generator or a good portable unit for camping, you don’t need to spend the big bucks on a commercial-grade generator. Even most contractors don’t use their generators all the time. So what we’ll be looking at in this review of the best 4000 watt generators, are machines that serve the needs of the home and camping user, as well as the general contractor. So we’re focusing on affordability and something that can power up both your refrigerator and air conditioner along with most of your regular appliances and lights for home / RV use.

Has Carbon Monoxide Monitor | Briggs & Stratton P4500

Alternatively, for contractors these generators will supply the wattage needed for a bunch of power tools, even heavy equipment like air compressors. One thing that you should keep in mind, is that none of the generators that we’ll be reviewing can provide 240V. They only deliver 120V and this means that you may not be able to use some equipment, like heavy tools and large air conditioners or furnaces when supplied with any of 4000 watt generators that we’ll be looking at.

We’re not going to be scraping the barrel, looking for the cheapest 4000W generators. Rather, we’ll be looking at striking a balance between affordability and long-term durability. Basically, we’ve chosen a good selection of quality 4000W generators that won’t break the bank. These are generators that have proven themselves to be reliable and we’ve done a good deal of research to see what actual users, like you and I, feel about the machines that they’ve bought.

This means that you can buy with confidence. When you’re hauling out your hard-earned cash on a product of this nature, you want something that’s going to serve you dependably for many years. This has been our number one consideration when choosing the best 4000 watt generators for this review.

Champion 100302 – Digital Hybrid Inverter

Best 4000 watt generator designed in a open frame to allow for a larger engine while still maintaining a small footprint. Quieter than a traditional gas generator.

best 30a generator — 50% quieter and 20% lighter than a traditional Champion 3500W generator.

Buy on Amazon

Features :

4000-Watt Digital Hybrid Open Frame Inverter Generator is one of the most innovative products on the market. Our advanced technology and innovative design will improve the way you power your life.
50% quieter and 20% lighter than a traditional 3500-watt portable generator.
Recoil start features Cold Start Technology
224cc Champion engine
4000 starting watts and 3500 running watts
Runs for 17 hours at 25% load (2.9-gallon fuel tank)
Low oil shut-off sensor
Quiet : 64 dBA from 23 feet
Safely powers sensitive electronics. Clean Power (less than 3% THD).
Quick Touch Panel offers fast access to controls
Economy Mode monitors power consumption in real time to reduce electrical load
RV Ready inverter
Outlets : 120V 30A RV (TT-30R), two 120V 20A household outlets (5-20R) and a 12V DC automotive-style outlet with a dual USB adapter and battery-charging cables.
Optional Parallel Kit (Champion 100319 50-Amp RV Ready Parallel Kit), with included standard 50-amp RV outlet, provides a clip-on connection which allows you to increase output by connecting up to two 2800-watt or higher inverters or digital hybrids.
Fully assembled CARB compliant i
3-year limited warranty and FREE lifetime technical support.

✓ View or download the MANUAL for the Champion 100302.

Overview

At its regular selling price, the Champion is the most expensive of all the models we’re reviewing here. Like the Westinghouse, this is also a digital inverter generator. It has the added advantage of a hybrid engine that can run on gasoline or propane. It also has the option to connect another Champion 100302 in parallel to double your power output. So, in that sense it beats the Westinghouse and goes some way in making up for the higher price.

Watch this VIDEO & See the Champion 100302 Up Close

https://youtu.be/PHcHG9IiZsU

You’ve got to love the 224cc, OHV engine that’s fitted to this generator. It’s one of the quietest and has really great fuel consumption. Like the others, this engine only has a recoil starter but with its advanced cold start technology, the Champion is one of the easiest starting generators around. It does to tend vibrate a bit more than many others though. On the plus side, emission levels are among the best and the Champion is both CARB and EPA certified. It sort of goes without saying that the engine is protected by a low oil shutoff.

Power output is what I’d expect from this class of generator – 4000 starting watts and 3500 running watts. Though when you look at the fuel consumption, the champion is an outright winner. At 5.1 kilowatt-hours per gallon, none of the 4000 watt generators in this review come close. So this means that despite having the smallest fuel tank of the lot (2.9-gaallons), the Champion will keep on chugging for 17-hours at 25% load. This is, in part, due to a fantastically fuel efficient engine. But the smart digital inverter with an economy mode also plays a role in this. It also gives the Champion one of the best noise levels of only 64dBA. I don’t know how many open frame generators of this size can boast a noise level below that of an average conversation.

Champion Power Equipment 100302. Best portable gas generator. Emergency generator. — RV ready, outdoor events, camping, emergency backup… (**Buy from Amazon**)

Another area where the Champion is a real winner is in the fantastic array of outlets. It has the regular 120V household outlets (2 of them), a 30A twist lock (TT30-R) 120V outlet, and a 12V battery charging outlet with a USB adapter. All the circuits (including the 8A 12V DC outlet) are protected by circuit breakers. In addition to this, if you’re using the parallel connection kit (Champion 100319 50-Amp RV Ready Kit), you can use a 50A twist lock outlet which is the best for connecting a transfer switch to your home.

With two generators in parallel, you’ll actually have a total current of 58A running power and 66.6A peak power. So there’s no chance of your generator overloading if your transfer box is fitted with a 50A breaker.

When we look at portability, the Champion comes up with mixed results. It’s one of the lightest at 81.6 LBS. But it doesn’t have a wheel kit. Though like all the others, you have plenty of grip for two people to comfortably carry this generator.

There are so many factors that place the Champion at the top of the list as the best 4000W generator. It has the best fuel consumption, the lowest noise levels, parallel connectivity, and it’s the only generator in this review to feature hybrid (dual fuel) operation. So, as much as I really like the Westinghouse for its excellent value, the higher price of the champion is certainly justified. It also comes with a 3-year warranty which always inspires confidence.

Westinghouse iPro4200 / Not Available

Best 4200W generator incorporating inverter technology. Excellent engineering makes this a top recommendation.

Best 4000 watt generator. Best gas generator. Small generator. RV ready generator. — 5.8 HP 212cc OHV 4-Stoke Westinghouse engine

Features:

3500 Rated Watts / 4200 Peak Watts (at Less Than 3% THD)
Outlets : Six 120V 20 Amp GFCI Power Outlets, Two USB Outlets
Engineered for Professional, Industrial Applications – Strong Enough to Run Power Tools and Job Site Essentials
Tough Steel Fuel Tank and Rugged Steel Frame
OHSA Compliant with Full Panel GFCI Protection –
212cc Westinghouse OHV Engine features Fuel-Saving “Efficiency Mode,” Overload Protection, and Automatic Low Oil
Shutoff for Added Safety
Extremely Quiet, Extremely Fuel Efficient: Low Noise Output
1000 Hour Warranty, Free Lifetime Technical Support – EPA, USFS, and CARB Compliant (Legal for Sale in California)
EPA / CARB Compliant
OSHA Compliant – Full Panel GFCI
22 hour run-time @ 25% Load / 16 hour run-time @ 50% Load
4.0 Gallon Gas Tank
Very Quiet : As low as 62 dBA. Quieter than a Traditional Portable Generator
Safe for Electronics. Clean power.
Weight : 82 lbs
1-Year Commercial Warranty and Lifetime Technical Support
Includes : Oil, Funnel, Tool Kit, Manual, and Quick Start Guide.

Ideal For : Power tools and equipment, lights, portable AC, microwave, laptop, and much more

Documents for the Westinghouse iPro42000 :

View or download the MANUAL
View or download the SPEC SHEET
View or download the QUICK START GUIDE

Overview

Of the 4000W generators that we’ve selected for this review, the Westinghouse iPro4200 is the second most expensive. Though we need to compare apples with apples and this generator, along with the Champion 100302 – Digital Hybrid are both inverter generators. The other two are conventional generators that don’t make use of an inverter and this makes them a fair deal cheaper.

Of course, many generator buyers are seeing the added value that you get when using an inverter generator. By now, it’s almost common knowledge that an inverter protects your electronic equipment. With electronic circuitry used in just about every modern appliance, an inverter is an obvious advantage. Along with greater fuel efficiency and lower noise levels when the generator isn’t supplying a large load, there are some added benefits to using an inverter generator. So when we compare the Westinghouse iPro42000 to the other 4000 watt inverter generators, the price starts to look much more attractive. I say this because the inverter is an obvious advantage and worth paying extra for. Even more so, when you consider the build-quality and specifications that this generator offers.

Having taken a detailed look at most of the generators in the Westinghouse lineup, I have come to the conclusion that these are spectacular generators. For an incredibly reasonable price, you’re getting a generator that can truly stand its ground alongside the best. So, in my opinion, the Westinghouse iPro42000 is the by far the best 4000 watt generator for its price. You can pay more and not get a generator that’s as good as this one.

The 212cc, OHV, 4-stroke engine runs like a dream, providing 5.8 HP. It has the power to manage the load requirement without straining. This generator is also surprisingly quiet for an open frame generator. I don’t have certified noise levels for the iPro42000, but what I can confirm is that users have commented on the smoothness of the engine, its quietness, and how easily it starts. This means that the absence of an electric starter isn’t too much of an inconvenience. You won’t be tugging endlessly on the recoil starter in cold weather.

The engine is great in terms of emission levels, meeting both EPA and CARB emission standards. Unfortunately, it’s not CSA approved and is, therefore, not legal for sale in Canada. I don’t think this means that it doesn’t meet Canadian regulations, it’s more likely that Westinghouse hasn’t applied with the Canadian authorities for CSA certification. Hopefully, they will do this at some point. The muffler is also fitted with a spark arrestor, so it’s fine for forests and national parks. Other safety features include low oil shutoff to protect the engine and OSHA compliant GFCI protection for the full panel. All the outlets are protected by circuit breakers and an Automatic Voltage Regulator (AVR) keeps the voltage stable and protects your equipment from power surges.

The power output is a bit higher than the 4000 watt spec that we set for this review, so it beats all of the others in terms of a higher surge wattage. A peak output of 4200W (35A) and constant power of 3500W (29A), is a good deal of usable power. You won’t have a problem running a 15,000 BTU RV air conditioner with this generator. But, with that kind of load, you won’t have that much power to spare. For a portable AC, a refrigerator (or 2), and most of your other household and camping power needs, the Westinghouse will deliver without a hassle. This, with the benefit of an electronic inverter, providing true sine wave current with less than 3% Total Harmonic Distortion (THD).

Fuel consumption is on the lower end of the scale, providing great economy. Like most inverter generators, it has an economy switch on the control panel that allows the generator to run at lower revs when the electricity demand is reduced. Thereby reducing your fuel consumption and noise levels. The result is a very impressive 22-hour runtime at 25% load from the 4-gallon gas tank. Giving the Westinghouse a very impressive 4.8 kilowatt-hours per gallon of gas.

The control panel is wonderfully easy to understand and logical. It has a total of six 120V household outlets in the Duplex format. Each group of two outlets has a dedicated circuit breaker positioned directly below the outlet for really easy identification. The outlets also have plastic covers, which is something that I really like because it protects them from dust and moisture.

One thing I find a little disappointing is that it doesn’t have a 30A outlet for an RV or transfer switch, nor does it have ports for parallel connection like so many other inverter generators. It does have a 5V USB port and warning lights indicating low oil and overload, as well as an indicator light telling when the system is ready for use and it includes a digital hour meter. Other than this, it doesn’t have too many bells and whistles. There’s no fuel gauge, volt meter or any of the fancy stuff that you find on many modern generators.

The Westinghouse provides you with a combination of sophisticated modern technology in the form of a great inverter and good old-fashioned, no frills, common sense. The rugged steel frame and steel gas tank indicate that this generator is intended to last. It weighs a very respectable 82-pounds and with the wheel kit (sold separately) it’s very portable. With a residential warranty of 3-years or 1000 hours and a commercial warranty of 1-year or 1000 hours, you know that Westinghouse has your back.

DuroStar DS4000S

I recommend getting the optional wheel kit so you can move it around easily. Trust me on this. it’s money well spent : DuroStar DS4000S-WK Wheel Kit

Buy on Amazon

Features:

Durostar 7 HP, air cooled OHV engine with low oil shutoff
Heavy duty steel frame with four point fully isolated motor mounts
Full power panel with oil warning light, volt meter, circuit breaker and power outlets
Run time 50% maximum output: 8 hours
Low oil shutoff protects engine
Super quiet muffler reduces engine noise
Max AC output : 4000-Watt / Rated AC output : 3300-Watt
4-stroke OHV single cylinder with forced air cooling system
Meets EPA and CARB Emission Standards.

Overview

DuroStar has earned reputation for manufacturing good generators that are really cheap, providing you with exceptional value for money. If you’re looking for one of the most affordable 4000 watt generators, that gives you good level of quality, the DuroStar is undoubtedly going to win you over. If you’re wondering if there’s any difference between DuroStar and DuroMax generators, there really isn’t. Both brands come from the same factory and many of the models are identical.

There may be minor differences in their specifications and the price may differ slightly for very similar versions of the same basic generator. In most cases, the DuroStar option will be slightly cheaper than one baring the DuroMax branding. Though, DuroStar generators aren’t usually CARB certified and that’s one of the downsides to this model – you can’t buy it in California. As much as I really prefer the Westinghouse iPro4200, I cannot deny that the DuroStar DS4000S is unbeatable when it comes to incredible value for money, simply because the DuroStar is so much cheaper. You won’t be able to find a better generator at this price. Not by a long shot.

This is a very conventional looking open frame generator and it doesn’t have an inverter. With that said, it’s a surprisingly quiet generator. With a rated noise level of 69dBA, almost as quiet as normal conversational voice, which is generally considered to be around 65dBA. The engine runs very smoothly and has a great muffler which is what contributes to the better than average noise levels for a generator of this size. It has quite a powerful engine, being a 7 HP OHV gas unit. The irony is that the DuroStar, which has substantially more horses than the Westinghouse inverter generator, doesn’t provide the same wattage. This generator has a peak (surge) power rating of 4000 watts and provides 3300 watts of continuous running power.

The extra horsepower also makes this generator a thirstier beast. It has a 4-gallon gas tank and this gives you runtime of about 8-hours at 50% of its rated load. This translates into a rather unimpressive 3.3 kilowatt-hours per gallon. As this is not an inverter generator, it doesn’t have the advantage of an economy mode. This is probably the biggest drawback to this generator. Though if you look at the astronomically low price, it would take 1000’s of hours before the extra gas cost actually starts to affect what you save on your purchase price.

It has a fuel gauge, so even though the tank will run dry sooner than more economical generators, you can at least keep an eye on how much gas is in the tank. It also has a voltmeter, which some of the more expensive generators don’t. This isn’t a digital meter, it’s the old-fashioned analog type with a needle indicating the output voltage. Though, I really can’t see how this makes any difference.

Like most 4000 watt generators in this class, the DuroStar doesn’t have an electric starter. Though, because it doesn’t take much to get the generator up and running, I don’t see this as a big deal. The control panel provides you with 2 X 120V household outlets and a 30A, twist lock 120V outlet for easy connection to your RV or a transfer switch connected to your house wiring.

Portability is fair, the DuroStar DS4000S weighs 90 LBS and the steel tubing frame wraps over the top of the generator, providing you with plenty of grip for two people to carry it. This frame design also provides reasonable protection for the steel fuel tank. You may well want a wheel kit to make it easier to move about, but you’ll be paying extra for this as the wheel kit is an option and not standard.

You’ve got to lift your hat to this generator, simply because of its price. Okay some aspects, like fuel consumption in particular, aren’t the best. But, all things considered, the DuroStar DS4000S is unbeatable value for money.

Sportsman GEN4000

Fantastic little generator. Inexpensive and dependable. One of the best cheap 4000 watt generators.

Features:

4000 surge watt/3500 running watt, 4-stroke OHV, recoil start with engine shutoff switch
High altitude use: this generator is not recommended for high altitude use above 3,000 ft.
Four 120-Volt outlets, one 120-Volt RV outlet and one 12-Volt DC outlet for battery charging; 120-Volt, 60 Hz.
Engine run time: 10 hours at 50% load; decibel rating: 69 dB
Automatic low oil shutdown, circuit breakers and UL listed electrical components
3.6 Gal. unleaded gasoline fuel tank
1-year limited manufacturer’s warranty
EPA approved
120-Volt 29 Amp operation

✓ View or download the MANUAL or the QUICK START GUIDE for the Sportsman GEN4000.

Overview

The closest rival to the DuroStar DS4000S as the best budget 4000 watt generator has to be the Sportsman GEN4000. This generator is a bit more expensive than the DuroStar and you may be wondering if it’s any better than the cheaper option. I can find a few reasons why the Sportsman will appeal to many buyers, making it worth the extra few dollars.

For one thing, this generator beats most when one looks at its fuel consumption. You can do the math, depending on how much you use your generator, if the fuel savings compensate for its price tag. But I would think that for most of us, the savings on gas over the years will justify the higher purchase price. I also find the general design of the Sportsman to be more durable. The frame provides fantastic protection from the inevitable knocks and bumps that a portable generator has to endure.

The Sportsman derives its power from a 212cc, 7HP, OHV gas engine which is EPA, but not CARB certified. This provides 4000 watts of starting power and 3250 running watts. So it has slightly less continuous power than most others, but this won’t really be noticeable – it’s the difference of a light or two. The big advantage is how little fuel it uses to achieve this. The gas tank isn’t all that big, only 3.6-gallons. Yet this is enough to keep the Sportsman running for 10-hours at 50% load. This calculates to 4.5 kilowatt-hours per gallon, only a fraction less than the Westinghouse which has the advantage of an economy mode. This probably makes the Sportsman the most fuel-efficient 4000 watt generator in its price bracket.

Noise levels are better than average for an open frame 4000 watt generator (69dBA). It has an automatic low oil shutoff, which is pretty standard on generators these days. The control panel is also more comprehensive than some others, in that you get a 12V battery charging outlet alongside 4 X standard 120V household receptacles. Though it doesn’t have the 30A twist lock RV plug. This is something that many users will find inconvenient, as a 4000 watt generator is the ideal size for a small to mid-sized RV which are usually fitted with a 30A inlet for a generator. Though this is about all I can really find to complain about the Sportsman. It’s not the only generator in this review that doesn’t have a 30A outlet.

As A Dual-Fuel Generator | Sportsman GEN4000DF

Best 4000 Watt dual-fuel generator. — Same features as the GEN4000, except it’s a dual-fuel model

Well, there is one more issue. The Sportsman is not designed for a wheel kit. So the only way to move this 97.6-pound brute around, is by carrying it. This is made easier with tubing that wraps over the top in a similar fashion the DuroStar. The only real negative aspect that users have mentioned is that the Sportsman isn’t the best when it comes to portability.

There are a few minor issues that can easily be ignored if you look at the Sportsman’s strong points. It’s a very durable 4000 watt portable generator and really isn’t thirsty at all. If fuel economy is big on your list of priorities, you really can’t pass this one up.

Is it worth paying extra for a dual fuel generator?

Environmentalists will insist that a hybrid generator that can use an alternative fuel source is worth its weight in gold. This is because propane burns cleaner than gas, so it releases less toxic emissions into the atmosphere.

From a technical standpoint, there are other advantages to using cleaner burning propane. Because there’s less carbon, your spark plugs will last longer and the carburetor will require less maintenance. It also eliminates the common problem of oil residue that can cause the generator to have problems starting – particularly if it has stood unused for a long period without draining the carburetor. So this means there’s no need to drain the gas from the generator or use fuel stabilizers.

Ultra-Quiet Dual-Fuel Inverter Generator | Champion 100263

Review : Champion dual-fuel inverter generator — As quiet as a conversation at 59 dBA. (**Buy from Amazon**)

Another practical advantage is the compact and safer storage that a propane tank provides. This is also a big plus factor when transporting your fuel. We all know what a hassle gas cans be. They can leak and spill quite easily, especially when filling up the gas tank on your generator. Gas cans also release unpleasant fumes. This is not only bad for your health, but can pose a serious fire hazard. Propane tanks are completely sealed and don’t have these problems. In addition to this, propane is compressed in the tank. So you get a larger volume of fuel into a smaller area. Generally, a 20 LBS propane tank will give about twice the runtime that you would get from a gallon of gas.

Many people have pointed out that propane has given them a distinct advantage when it comes to availability. During a hurricane, snow storm, or earthquake, roads are often inaccessible. This makes it impossible for fuel transporters to reach the gas stations. It’s at this very time when the demand for gas is at its highest. So being able to use propane when there simply is no gas available, can make all the difference. Propane can also be stored indefinitely and it has other uses, like the barbecue.

With all things considered, it’s quite clear why propane and dual fuel generators have grown in popularity. The higher cost isn’t too much. Basically, you’re paying for an extra connection for a propane hose, a pressure regulator, and a valve that switches the supply between the gas tank and the propane inlet.

Can a 4000W generator supply enough power for your RV or home?

There’s no clear cut answer to how much power you need from a generator. For home use, in particular, a portable generator will always require some compromise. Even the largest portable generators that supply 12KW -15KW, won’t always be sufficient for the average household electrical needs. When we look at RVs, a 4000W portable generator is often the perfect size. If your RV is fitted with a 30A socket, it’s designed to run off a generator of about 4000W. At 120V, 4000 watts works out at 33.3A. Larger RVs, with a 50A socket, should, ideally make use of a 6Kw generator or more. Though, you can use a 4000W generator without too much compromise.

The main thing to consider is the size of your air conditioner. In an RV, this is going to be your biggest electrical appliance. A 15,000 BTU AC draws about 3,500 watts to start and then runs at about 1,500 watts. So, if you’re using a 4000 watt generator for this size air conditioner, you’ll be seriously limited as to what other appliances you can use at the same time. On the other hand, a 7,000 BTU air conditioner will work perfectly. In this case, you’ll need around 1,700 starting watts and only 600 watts of continuous power for your AC. This would be roughly the same consumption for a large refrigerator.

Using energy star appliances makes your generator all the more useful. Generally, your air conditioner and refrigerators will use the most power. I wouldn’t recommend heavy-duty electric equipment like heat pumps and large furnaces for a 4000 watt generator. Even then, an energy star heat pump may work if it’s not too powerful. If you’re using energy star appliances, you will be using up to half the wattage that would be required for a similar appliance that doesn’t have an energy star rating. This not only increases the amount of appliances that you can use, but will drastically reduce your fuel consumption. You’ll be saving money and you’ll get longer runtimes from a tank of gas.

When calculating your generator needs, draw up a list of the appliances that you intend using. You’ll need two columns for your wattage. One will be your running watts, meaning the power that these appliances use constantly while they’re switched on. The second column will be for your starting watts, the amount of power that’s required for a short period when certain appliances start. You’ll probably find that your wish list calculates to a lot of watts – particularly, your starting watts column.

This may end up leading you to believe that you’ll never get an affordable generator to meet your needs. This is where you need to apply some common sense. Firstly, try and figure out if everything that you’ve listed is absolutely necessary. Though, even more importantly, you should consider which of these appliances will be used at the same time. Can you manage your power better when using a generator? For instance, if you want to use the microwave for a few minutes, you could always switch the AC off for this short period without much inconvenience. This approach to adjusting your power consumption to meet the wattage of your generator should mean that you can use most of the electrical equipment around your home if you put a bit of thought into it.

Generator Wattage Calculator

Before you can begin to assess your wattage requirement in order to ensure that buy the correct generator, you need know your power consumption needs. The best way is to check the individual appliances. They will often have tag which could give you a power rating in watts (W); Horse Power (HP) or Amps (A). You might be able find this information is your user’s manual or by contacting the manufacturer.

Because your generator will be rated in watts, you may need to convert the power rating displayed on your appliance.

Converting Horse Power to Watts:

1 HP is equivalent to 745.7 watts. So you simply multiply your horsepower by 745.7.

W = HP X 745.7

For a 1.5 HP sump pump, your sum will look like this:

1.5 X 745.7 = 1118.55 watts.

Converting Amps to Watts:

You may remember your school teacher once giving the equation P = VA. This is the method for calculating Power (watts) in relation to the voltage (V) and the Amperes (A). So you basically multiply your amps by your voltage.

For a 15A, 120V appliance your sum will look like this:

15 X 120 = 1800 watts.

Appliance Wattage list

It may not always be possible to find the power consumption figures for all your appliances. In this case you’ll need a reasonable estimate based the average power used by this type of equipment. The list below serves as a basic guide to typical wattage ratings for common appliances that can be used with a 4000 watt generator. These are based on estimates and cannot be considered as an accurate assessment, though it will give you a good idea of what you need.