Generator Runtime on 5 Gallons of Gas

So you got yourself a generator but not sure how many gallons of gas it uses in a given timeframe? Here's everything you need to know!

yellow champion generator next to white propane gas tank

It’s kind of funny because you honestly buy a generator with the hope that you’ll never have to use it. No, generators aren’t always subject to being used just for emergencies, but that’s kind of what they’re known for. And when it comes to the topic of them, one specific question always seems to be asked by so many. How long will a generator run on 5 gallons of gas?

We wish it was as easy as just answering that question and moving on, but that specific question requires much deeper research. Quite honestly, there are many different answers to the question that will end up being correct, and that’s simply due to how dynamic of a question it is.

Yeah, we know, all of that just sounds like an excuse, right? No worries, as we’re prepared to dive headfirst into this to provide the most accurate and practical answer (or answers) that we can. All just for you! That’s the power of the internet right there. Anyway, let’s not get sidetracked here. How long will a generator run on 5 gallons of gas?

Alright…here’s the answer

Believe it or not, there are actually quite a few “experts” and online articles that have answered this question directly. The general consensus seems to be that a typical generator is going to run for 8 hours on 5 gallons of gas. That’s not the end of the story, however, as there’s a really good chance that you could get more or less of 8 hours after your generator has consumed 5 gallons of gas.

There are quite a few factors that can affect this time, and the first is honestly the brand of the generator you buy. For example, some Honda generators are touted to run for up to 24 hours on only 2.5 gallons worth of gas. Doing the math really quickly, that would mean that some Honda models will last for upward of 48 hours on 5 gallons of gas. Clearly, that’s quite a massive increase from 8.

Past the specific brand you go with, there are three main factors that can attribute to generator efficiency (regarding fuel consumption). Those are the load the generator is handling, the fuel type it uses, and also the specific type it is.

The load

In the simplest of explanations, the load of a generator is whatever you’re using it for to access power. Whether you’re using it to power appliances, smaller devices, equipment, etc., anything that’s using power directly via the generator is a part of its overall load. This is going to change for everyone as everyone is going to use a generator for different reasons (sometimes for the same reasons).

Here’s another factor that has to be accounted for, there are different types of generators out there that are designed for specific reasons. Each of the different types will dictate how large of a load can even be handled, in the first place.

The main types of generators

There are three main types of generators that you’ll see on the market. That being portable, inverter, and standby models, and each is ideal to utilize in their own ways.

Portable generators

As their name implies, portable generators are just that…portable. They aren’t the smallest generator type on the market, but they’re also not the largest. They’re kind of directly in the middle of the other two and are nice for camping and other likewise adventures. For powering an entire house, let’s just say that this type of generator really isn’t going to get the job done.

Standby generators

One could consider standby generators as the alpha male of the trio of generators on the market. They’re not the models that you want to have to lug around everywhere, as they’re pretty much meant for home use. Due to such, they’re designed to take on significant loads, so they may burn through gas a lot quicker than the smaller generators out there.

Inverter generators

We finally get to the smallest and most portable generators out there: inverter generators. In addition to their smaller size, which is only typically suitable for electronics and such, they’re also designed to be incredibly fuel-efficient. In general, they’re going to consume less gas than any other generator out there.

What are some of the fuel types available for generators?

It would seem silly to answer the question, “how long will a generator run on 5 gallons of gas” and also bring up fuel types, right? After all, the question kind of points out that gas will be used as the fuel type. Yet, past the fact that there’s clearly more than one gas type out there, it’s something that should be discussed. So, that’s what we want to do to wrap this up.


Propane generators definitely have their fair share of advantages such as propane’s shelf life. That said, when it comes strictly to talking about fuel efficiency, they fall short of the other main fuel types out there. While not as efficient, they’re really a nice option for those who don’t plan to use their generators very often.


Gasoline is easily one of the most popular and readily accessible fuel types on earth, so it makes sense that many generators would run off of it. Regarding its efficiency, it’s more efficient than propane. However, while it could be argued it’s the most common fuel source for generators, it’s not the most efficient.


When it comes to efficiency and performance, diesel generators pretty much stand head and shoulders over the competition. Sure, they’re typically more expensive than the others (and diesel itself is more expensive than gasoline) but they’re also going to run better and probably longer.


Oh…you didn’t see this coming, did you? Okay, maybe you did, but we think it makes for a better story if you didn’t. Anyway, back to business, there are also generators that are known as tri-fuel models (also known as multi-fuel or hybrid-fuel models). As the name suggests, these types will allow for multiple different fuel sources to be used. How great is that?

How long will a generator run on 5 gallons of gas?

Wait…haven’t we already answered this question? Yes, but we just wanted to steer back to the point that the question can have so many different answers. It was never going to be cut and dried, unfortunately. Do you know what another interesting question regarding generators is? How about if they’re waterproof or not? Come on, you know you want to know!