How Much Gas Will Your Generator Use?

A 5kW portable generator on gasoline will use 0.75 gallons per hour. On the other hand, a 6kW inverter generator will use 0.14 to 0.17 gallons of propane in an hour. Natural gas consumes the most amount of fuel with 1.42 gallons per hour rate. However, the gas consumption rate of your generator depends on various factors like generator model, size, fuel type, fuel efficiency, generator power rating, etc. 

So, to know how much gas will your generator use, compare the generator types and fuel types first. 

To know more, consider all the factors related to gas consumption. Follow the article to gain insight into the details of this matter.  

Gas Consumption of Generator: Quick Overview

The gas consumption of a generator depends on the generator type, wattage, and the fuel used. 

Generator TypeGenerator CapacityFuel TypeGas Consumption/HourGas Consumption/DayCost
Portable Generators5 kWGasoline0.75 gal.18 gal.$2.6 per gal.
Built-in Generators7 kWNatural gas 1.42 gal.34.08 gal.$20.4 per thousand cu.-ft.
Inverter Generators6 kWPropane0.14 – 0.17 gal.3.36 – 4.08 gal.$3.38 per gal.
Diesel Generators8 kWDiesel0.5 gal. 12 gal. $4.34 per gal.

The answer to the gas consumption rate of a generator relies on the type of generator and fuel first. 

How Much Gas Does a Generator Use?

You might wanna compare these factors first to determine which one you wanna get. Now, let’s dive into the details of how can you calculate the gas consumption rate. 

How Much Gas Does A Generator Use Per Hour?

How Much Gas Does A Generator Use Per Hour

To calculate the gas consumption rate of your generator, you need to find out some information such as 

  • Check the manual for power output (kW).
  • Find out the generator’s fuel consumption rate at full load (LPH or GPH) in the manual.
  • Now, convert it to the unit based on the used gas. 
  • Check the manual for fuel efficiency (BTU or GPH). 

Formula: Gas consumption rate in an hour = Fuel consumption rate (GPH or cu-ft per hour) x Fuel efficiency (BTU/GPH) ÷ Power output (kW)

Now, an 8 kW generator has a 0.5 GPH fuel consumption rate with a 100 BTU/GPH fuel efficiency. So, the gas consumption rate per hour is =0.5 x 100 ÷ 8 = 6.25 GPH. Convert it to the appropriate unit for the gas used.  

So, for example, to know how much gas does a 7500-watt generator use, follow the same procedure.  

How Much Gas Does A Generator Use Per Day?

Now, it is basically easier to calculate the gas consumption rate per day. Just multiply the per-hour rate by 24. Or the number of hours you use the generator. 

So, for the above example, the gas consumption rate per day for 8 hours of usage = 6.25 x 8 = 50 gallons per day. For natural gas, the unit will be cu-ft/day. Now, 1 cu-ft of natural gas = 0.012 gallons

So, for example, if you want to know how much gas does a 6500-watt generator use, use the calculations above to find out. 

How Much Gas Does A Generator Use In An RV?

Usually, a 5 kW generator will use about 1 gallon of gasoline per hour in an RV. But for propane gas, the amount goes up to 0.5 gallons per hour at 50% load. Gas consumption in RVs depends on various factors such as used appliances, generator size, wattage, load, fuel type, appliances, RV type, usage pattern, etc. 

How Much Gas Does A Generac Generator Use?

A small 2 kW Generac generator uses about 0.15 to 0.20 gallons of gasoline per hour. But a larger Generac generator with a 22kW of power rating will consume about 2.4 to 3.4 gallons of natural gas at half load. On the other hand, a Generac generator burns 2 to 4 gallons of propane per hour depending on the specific model and size. 

Again, the gas consumption rate for Generac generators depends on the generator size, type, fuel used, fuel efficiency, power rating, etc. 

Now, you can check with professionals to know for example how much gas does a 3000-watt generator use.

How Much to Pay for Generator Gas Consumption?

The cost of generator gas consumption also depends on the fuel used and the generator usage. Let’s see the gas consumption price per gallon for different fuels. 

  • Gasoline: $2.6 per gallon. 
  • Propane: $3.38 per gallon. 
  • Diesel: $4.34 per gallon. 
  • Natural Gas: $20.4 per thousand cubic feet. 

But, there are ways to control the gas consumption rate for your generator. Let’s see how. 

How to Decrease Generator Gas Consumption?

You can follow the below steps to decrease the gas consumption rate. 

  • Convert the generator’s motor to a low voltage. 
  • Run only the essential appliances. 
  • Don’t use the generator under 50% load. 
  • Do not overload the generator. 
  • Service your generator whenever necessary. 

These steps will help you to lose gas consumption rate as the costs will be down too. 


So, now you know what factors to consider to know the gas consumption rate and cost of your specific generator. Also, the calculation method of the per-hour and day rate for generator fuel is useful when choosing the right generator for your home.

Frequently Asked Questions (FAQs):

Can You Run A Generator 24 Hours A Day?

Theoretically, yes you can run your generator as long as it has fuel, and it may be 24 hours. As long as you have a constant supply of fuel, the generator will run. 

Do All Generators Need Gas?

Although all generators need fuel and most of them run on gasoline, solar generators do not need fuel. Solar generators draw energy from the sunlight. 

Which Is Better Gas Or Electric Generator?

Electric generators have the advantage of power duration over gas-powered generators. Battery-powered generators need less maintenance and service than gas generators. 

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