How Much Natural Gas Does a Generator Use?

Residential standby generator

People find generators useful for many situations, such as living off the grid or preparing for a natural disaster. When searching for a new generator, whether you want to install it yourself or have an electrician perform your generator installation, you must consider its function.

Manufacturers make several types of generators to satisfy different needs. Thus, the answer to “how much natural gas does a generator use?” varies greatly depending on what kind of generator you get.

Not all gas-powered generators even use natural gas as their energy source. Keep reading our guide to find out more about different types of generators, the cost of fuel, and how much you need to pay to keep your generator running.

Types of Generators


Because larger generators consume more fuel than smaller ones, you must decide which model works best for you based on what you plan to use it for.

Inverter Generator

An inverter generator refers to the smallest of the generators available for purchase. Most people buy inverter generators to charge smaller electronic devices, such as computers or car batteries. Though some run on fuel, you can charge others with electricity.

Portable Generator

Portable inverter generator

Portable generators are larger than inverters. Thus, they can provide electricity to larger devices such as kitchen appliances. These work great for traveling but can’t sustain multiple devices for a long time.

Some portable generators come with a large capacity tank, meaning you can wait longer before refueling. However, these generators still won’t work to power an entire house.

Standby Generator

If you need an emergency generator, standby generators make the best choice for you. They have the power to supply electricity to your entire home for several hours during an emergency. They require a significant amount of fuel to run but are helpful in the event of a disaster.

Type of Fuel

Depending on the model, generators can take four main types of gas: natural gas, diesel, gasoline, and propane.

Natural Gas Generator

Natural gas generator next to home

Since this article discusses “how much natural gas does a generator use,” we will start by discussing this one. Natural gas generators are best if you have lines already connected to your house. You can easily connect the generator to these lines for a constant fuel source.

Using natural gas makes a better option than some of the other fuels on this list, such as diesel, but it is still not eco-friendly. They eat up a large amount of fuel quickly.

Diesel Generator

Diesel burns the slowest, meaning that you will need less fuel to power these generators for longer. However, this fuel creates a lot of pollution and proves bad for the environment.

Gasoline Generator

Gas generators consume around 0.75 gallons/hour when powering a home. They tend to have a better price point than other generators.

However, gas generators need a lot of fuel. Furthermore, most people search for gasoline during an emergency, meaning you may not find the necessary fuel to keep your generator running in these situations.

Propane Generator

Propane generators make a good alternative to natural gas if you do not have lines connected to your home. They are effective and have large fuel tanks. For example, you can power your house for about a week with a 500-gallon propane generator.

Light vs. Full Load

Generac generator beside brick home

An electrician may ask whether you need your generator for a light or full load. Essentially, they want to know whether you need a generator for a full house (full load) or smaller electronics (light load).

When shopping for generators, companies normally mention their capacity at a 50% load (essentially, 50% of the available power). Thus, you must overestimate how much power you will use, as you are more likely to use a generator at a 100% load.

How Much Natural Gas Does a Generator Use?

If you want to buy a natural gas generator, you must consider the size. The more watts a generator can handle, the more natural gas it will burn. The varying sizes of gas generators mean that you may use 1.86 cubic feet (1,000W with 25% load) to 222.9 cubic feet (30,000W with full load) of natural gas/hour.

You will need approximately 7.43 cubic feet of natural gas to create 1 kWh of power. To calculate the fuel consumption per hour of your generator, you can use the following formula:

Generator Wattage x Load Wattage x 7.43 cubic feet / 1,000

How Much Does It Cost To Run a Generator for 24 Hours?

Generator painted to match house

Some common appliances and their approximate watt load (per hour) include:

  • New Television: 80 watts
  • Coffee Machine: 600 watts
  • Lights in One Room: 60 watts
  • Central AC: 3500 watts
  • Fridge: 780 watts
  • Microwave: 1800 watts

To determine the size of the load your generator would handle, think of all the devices you use. Find their approximate watts per hour and determine how much you would use them while your generator runs.

Then, calculate the wattage for a set amount of time. For example, if you plan to buy a standby generator for power outages of three days, determine your average hourly watt usage. Then, multiply that number by 72 hours.

By calculating the approximate number of watts you will use, you can better estimate the size of the generator that you need.

You can expect the following approximate generator fuel consumption in 24 hours on a full load. It is important to note that these reflect an average price and that the varying cost of fuel in Oklahoma will affect the overall price. 

  • 7 kW natural gas generator: 2,832 cubic feet (118 cubic feet of generator use per hour)
  • 8 kW diesel generator: 12 gallons (0.5 gallons of fuel per hour)
  • 5 kW gas generator: 18 gallons (0.75 gallons per hour)
  • 6 kW propane generator: 34.08 gallons (1.42 gallons per hour)

Looking To Install a Generator in Oklahoma City, OK?

We can help you install a standby generator in addition to answering the question, “how much natural gas does a generator use.” Visit the Blue Sky Electric contact page to schedule a consultation in Oklahoma City, OK.