How Long Can You Run a Generator Continuously?

How Long Can You Run a Generator Continuously?

How Long Can You Run a Generator Continuously? You may be wondering how long you could run a generator before it runs out of gas. It’s not an easy question to answer, but we can give you some guidelines for estimating the amount of fuel that will be needed for your generator.

The first thing is to estimate how much power your generator needs are and then calculate the number of hours required to produce that power using the formula below:

  • Power (watts) x Time (hours/day) = Total Watts per Day
  • Total Watts per Day ÷ Voltage (Volts) = Kilowatt Hours Per Day
  • Kilowatt Hours Per Day x Days Needed = Kilowatts Required

So on average a generator can run continuously for about 10 to 24 hours on a full tank - and that’s only if you use it sparingly! However, this can vary depending on the tank’s size and fuel type your using.

Fuel Tank Size

Tank size is another factor that may influence the run time of a generator is the size of the tank. A large tank requires more fuel than a smaller one. That’s why it provides a lengthier run time.

A smaller generator, however, does not run for a long period. Engines in vehicles are made for continuous use. Generator engines are not the same. When used beyond what’s recommended, it may overheat, which you do not want to happen.

Once it overheats, it may get damaged, so it’s always advisable to run a generator within 24 hour mark or less to reduce stress on the engine. 

But how about a natural gas-powered generator? Well, they can run for more than 200 hours, similar to other prime power generators that are used at workplaces.

As long as there is enough supply of natural gas, it will not run out as easily as you imagine. Like other generators, it requires a few minutes of rest. 

Fuel Types

There are factors that affect how long you can run your generator. Some of them include the fuel type, the fuel tank’s size, and the stress on your generator. The durability and maintenance of a generator may also play a significant role. 

The most commonly used fuels are propane, diesel, gasoline, and natural gas. Diesel generators are popular for a reason. Considered the top favorite among consumers, a diesel engine burns less fuel, protecting it against any damage and preserving its quality.

Diesel Generators

Diesel generators can run for around 10 to 24 hours of continuous use and have been increasing in demand over the past few years.

Homeowners have switched to diesel-powered generators because they are competitively priced and efficient as well. A perfect home or office backup for power outages, diesel generators have a maximum running time of 24 hours.

Propane Generators

The propane generator can run for up to 12 hours but is not as efficient as diesel Generators. It consumes higher fuel, causing you more money over time.

The energy a propane engine produces is less than that of diesel or gasoline. It only provides around 9200 BTUs in a single gallon for one hour.

A propane-fueled generator, on the other hand, is not as long-lasting as a diesel engine. Generators that use gasoline are quite similar to propane. Its run time ranges from 10 to 13 hours. 

Gasoline Generators

Gasoline generators are quite similar to propane and can run for 10 to 13 hours and can produce approximately 11400 BTUs. Gas is another top option for many because it is easy to acquire and buy.

But it is highly flammable and dangerous, especially when stored in a large quantity.

Generators with at least a 2-gallon fuel tank can run for a maximum of 10 hours. But a gallon cannot supply electricity to your home or office for more than five hours.

But you can try an inverter generator as it provides an environmentally friendly mode that fluctuates according to the load requirements. 

Dual Fuel and Single Fuel Running Time

A dual fuel generator has a lengthier run time than a single fuel type and can keep your home or power up your appliances for up to 13 hours. 

How does it work? As the name indicates, this kind of generator relies on double tanks of fuel, increasing its running time and longevity. That means you can get your work done while meeting deadlines and avoiding conflicts in the future. 

But that does not mean a single fuel generator is not worth the price. If you are on a tight budget or the power outage in your location usually takes an hour, a single fuel generator should be on top of your mind.

It can keep your office or home well-lit while helping you save some cash over time. But if you have an extra budget and the electricity outage lasts for hours, a dual fuel generator will never be a disappointment.

Yes, it is expensive. But it is worth the cost. Before making any buying decision, it is helpful to identify your needs. It really helps! 

Portable and Standby Generators 

Because of their size, portable generators are used for recreational uses. Whether you have a hiking or camping trip planned, a portable generator will be your best bet.

They can power appliances and even your home during an electricity outage. Portable generators are also an incredible investment for those working on a construction site.

But how about their run time. Well, they can run continuously for a particular amount of time. Proper and regular maintenance is required to keep them damage-free and functional over the years.

When looking for a sturdier option, a standby generator should be on top of your list. With its bulky size, a standby generator is excellent for long-term use.

Its engine is also efficient and can withstand the test of time. Most manufacturers claim that a standby generator can last for approximately 500 hours, which is equivalent to 3 weeks.

Can You Run a Generator Overnight? 

Of course, you can run a generator overnight. But there are a few things to expect. The most common headache is the noise, if you’ve used a generator in the past then you know they can get loud.

Fortunately, the advancement in technology more generators are eqipped with a silent operation mode. However, they are costly.

Another problem when you always run your generator overnight is the presence of carbon monoxide (CO).

It is recommended to never use a generator inside your garage or home, although the windows and doors are open. Be sure to use a Genset 20 feet away from your home.

It is also advisable to install battery-operated and advanced CO detectors. Generator theft is another problem you may experience, particularly when you have a portable one.

How to Find a Long-Running Generator? 

Standby generators are the number one choice for home or office backup power over an extended period. Unfortunately, they can cost you an arm or a leg. Currently, their price rate ranges from $2,000 to $20,000. 

But it is always possible to find a portable generator with a reliable run time, although it is available at a competitive rate. Below, we gather some tips you can follow and help you pick the right one.

Things To Look For

Fuel Type That Runs The Longest

Many types of generators are available in today’s market. But diesel generator stands out from the rest. Recognized as the most efficient option, a diesel generator is developed to run for a more extended period.

If you want to invest in a generator that guarantees a long-lasting performance during a power outage, a diesel one is highly recommended. 

Large Fuel Tank

It is a big mistake to refuel a generator while it is running. When gasoline is spilled on a hot engine, it can cause fire or even an explosion.

Before refueling your Genset, turn it off and let it cool down for a few minutes. Yes, it is a hassle. If you want to avoid frequent refueling, why don’t you consider a generator with a large fuel tank?

Although it may be costly, it can maximize run time and take your experience to the next level. 

You have a busy schedule, but spending time to study any available generators online is worth it. While there are multiple brands on the market, check and examine every model’s stats and specs before making a purchase.

More than that, read actual client reviews. Get rid of products with limited run time. Always direct your attention to a brand trusted by most customers for your convenience. 

A propane power home backup is not as efficient as a diesel generator. But it can be a fantastic alternative to a diesel-powered home or office when used with two or more fuel tanks.

How is this possible? Leave it to an expert. Be sure you work with an experienced and capable professional to enjoy a better result. 

Can You Damage Your Generator If You Run It Continuously? 

A generator is used as a power backup source. That means they are not developed for continuous use. But if you run it continuously, the performance of its engine may decline.

Sometimes, the engine may get damaged, requiring immediate replacement and resulting in unexpected expenses. If a longer run time is your concern, pick a generator with a large tank. 

This is where proper and regular maintenance can be a lifesaver. If it is your first time using a generator and you do not have any idea on how to keep its performance in check. You have come to the right place! 

Always Check the Air Filters

The air filter of generators accumulates dirt, dust, and grease over time. A dirty air filter can cause damage to cylinder walls, pistons, valves, and other internal engine parts.

When left unattended, it leads to poor engine performance and excessive oil consumption. So, be sure to keep them clean. Then, have them replaced after a month. 

Change the Oil in an Older Generator Every 24 Hours

If you have a newer generator, you can change the oil every 100 hours. You can also refer to its instruction manual, or you can ask for advice from someone with prior experience. 


You always run your portable generator for more than 8 hours every day. You refuel the tank while the generator is running. But it is time to change that habit!

Using a generator beyond its run time can damage its engine, leading to more costs. If you need a generator with a longer run time, a standby Genset will be a worthwhile investment!

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