How Much Gas Does a Generator Use to Power Your House?


When your power goes out, a generator can be a lifesaver. The downside, though, is fuel consumption. A traditional gas generator can go through gas quickly. If you aren’t prepared, you can lose the ability to power up before you’re ready. This article will help you:

  • Determine how much fuel you need
  • Learn to calculate your electricity consumption
  • Understand what EcoFlow’s Smart Generator (Dual Fuel) has to offer

How Much Fuel Does an EcoFlow Smart Generator Use?

Fuel consumption with any fossil-fuel-powered generator isn’t a set number. It depends on the type of generator you have, the kind of fuel you use, and your electricity consumption. Understanding those factors will help you determine how much fuel consumption you should expect.

The EcoFlow Smart Generator (Dual-Fuel) has a 5.4kWh capacity on gasoline and 20kWh with liquid propane. It runs for 3.5 hours on 1.05 gallons of gas, so it will burn about 0.3 gallons per hour at half load. A full 24 hours operating at 50% capacity will go through 7.2 gallons of gas (0.3 gal/hour x 24 hr = 7.2 gals). If the cost of gas is around $2.50 per gallon, it will cost $18 for one day (7.2 gal x $2.50 = $18).  That cost would double to about $36 per day at full load.

However, there are ways to reduce the cost. Propane is a cheaper (and cleaner) fuel solution than gasoline, and generally, you can get more energy from a propane tank.

Propane is also much easier and safer to store in bulk, and it has a much longer shelf life than gasoline, which begins to degrade after three months. 

You can also hook EcoFlow’s Smart Generator to other non-fossil-fuel-consuming portable power stations like the EcoFlow DELTA Pro to improve fuel efficiency and lower costs. 

EcoFlow Power generators - EcoFlow DELTA Pro

How Does a Gas Generator Work?

A gas generator creates electricity from mechanical energy. Similar to a traditional car, an internal combustion engine burns fuel to spin a shaft. That motion provides the mechanical force needed to generate a current. The motor spins a shaft that rotates an armature (electromagnet). The rotating armature spins and creates mechanical energy, which is converted into electrical energy.

With the EcoFlow Smart Generator, the dual fuel function lets you switch between gasoline and propane to create internal combustion. The dual fuel design helps ensure better fuel efficiency and gives you more options to refill.

Advantages and Disadvantages

As with any power solution, there are pros and cons to using a gas-powered generator.


  • Gas generators have relatively low — but ongoing — maintenance costs
  • You can re-fuel anywhere there’s a gas station or hardware store that sells propane (LPG)
  • Connect to a portable power station to maximize impact and reduce costs
  • Dual fuel options let you run on the most efficient and low-cost fuel source


  • Gas generators are considerably noisier than solar generators
  • Fossil-fuel-powered generators emit carbon monoxide, which can lead to sickness or even death without adequate ventilation
  • You can’t operate a gas generator inside — they must be installed at least 20 feet away from your house
  • Gas generators emit greenhouse gases, negatively impacting climate change. Propane is a cleaner fossil fuel resource but still generates harmful emissions
  • You need sufficient fuel on hand to continue generating electricity
EcoFlow Power generators - Electric generator

How to Calculate Fuel Consumption of Gas-Powered Generators

The most accurate way to calculate fuel consumption starts by determining the electricity requirements of the appliances and devices you want to run.

Here’s how.

Calculating the Wattage of Household Appliances

  1. Identify the wattage requirements of your appliances. Survey the starting and running wattage requirements of the appliances and devices you plan to plug into the generator. You can usually find the wattage requirements labeled on the appliance, but we’ve also compiled the starting and running watts of typical household appliances in the table below. 
  2. Convert volts/amps to watts. If your appliance’s power requirements are in volts or amps, you can calculate an appliance’s running watts with this equation: 

Volts (V) x Amps (A) = ​​Watts (W)  

  1. Count the running watts of your appliances. Add up the running watts of the appliances you plan to use — does the total exceed the running watts listed on your generator? If so, you should consider buying a generator with more output capacity.
  2. Factor in starting watt requirements. Identify the appliance with the highest starting wattage. Add that appliance’s starting wattage to the running wattage total.
  3. Calculate the sum. That final number is the total starting watts you need from your generator.  As discussed above, to avoid overloading your generator, do not exceed its starting watts rating.

Starting and Running Watts of Typical Household Appliances 

ApplianceRated (Running) WattsStarting Watts
Washing Machine12002300
Light Bulb60-750
Coffee Maker10000
Clothing Iron15000
Toaster Oven12000
Curling Iron15000
Space Heater20000
20” Box Fan200350

Wattage of the Generator

A gas generator’s wattage measures the maximum amount of electricity (watts or kilowatts) it can produce instantaneously. The Ecoflow Smart Generator can operate at 1800W (Peak Value 1900W) capacity burning gas and 1600W (Peak Value 1700W) using propane (LPG).

It can also be helpful to know how much electricity it can generate before refilling. This is measured in watt-hours or kilowatt-hours (kWh), also often used to determine battery storage capacity.

The EcoFlow Smart Generator has a run time of around 3 hours on a full tank, and the maximum amount of electricity it can produce running at full power is approximately 5.4kWh. With a standard propane tank (LPG), the maximum amount of electricity the Smart Generator can produce is 20kWh 

Remember that’s the operating capacity for one full tank running at maximum power — if you have sufficient fuel stored, you can keep the generator going until you run out.

Formula for Calculating Fuel Consumption and Cost

Fuel consumption per kWh of electricity is determined by the amount of electricity produced and how much gas is required to generate it. Manufacturers typically provide the specs for the maximum kWh a generator can produce on a single tank. 

Fuel consumption (gallons) = amount of fuel / total electricity produced (Wh or kWh) 

Example calculation

For the EcoFlow Smart Generator, the gas tank is 1.05 gallons. With a maximum electricity output of 5.4kWh on a full gas tank, you can use the following calculation to estimate consumption.

1.05 gal / 5.4kWh = 0.19 gallons of gasoline per kilowatt-hour.

At an average gas price of $3 per gallon, generating 1kWh of electricity will cost you about $0.57 — over triple the average cost of on-grid electricity in the US.

Factors That Affect Fuel Consumption of Gas-Powered Generators

  • Fuel storage capacity
  • Electricity consumption
  • Frequency and duration of use
  • Temperature and weather conditions
  • Generator maintenance
Fuel - Fuel container

Tips for Reducing Fuel Consumption of Gas-Powered Generators

To reduce fuel consumption, you can take several steps. These aim to either improve the generator’s performance or reduce your electricity consumption.

  1. Power fewer appliances. You will consume less fuel if you connect fewer appliances to your generator during a blackout.
  2. Service your generator regularly. Change the oil and clean the components regularly for optimal efficiency. Gas generators typically require more frequent maintenance than propane.
  3. Manage the load you’re powering. Try to keep the generator running at between 50% – 80% of output capacity.  Avoiding extremes will keep the generator running smoothly for longer.
  4. Use alternative power sources. Connecting your generator to a EcoFlow DELTA Pro portable power station or solar generator will help you get more out of your Smart Generator for longer.
EcoFlow DELTA Pro Portable Power Station - EcoFlow Official

Other Types of Generators

Besides the gasoline and dual-fuel generators like the EcoFlow Smart Generator, you can purchase several other types.

Diesel-Powered Generators

Diesel generators are some of the most powerful backup generators on the market. They use diesel fuel, which can be challenging to store. They also tend to create a higher noise and pollution level than any other generator type.

Propane-Powered Generators

Propane generators create substantially less pollution, toxins, and fumes than diesel or gasoline generators. The main downside is that they use fuel more quickly than other types of generators do.

Solar-Powered Generators

Solar generators charge by attaching solar panels to a portable power station or power kit to generate and store electricity. Solar generators are environmentally friendly and create very little noise. They’re also safe to operate indoors. The downside is that you may need more electricity than your solar array can generate if you don’t purchase a system with sufficient electricity storage and output capacity.

EcoFlow Power generators - EcoFlow DELTA Pro


A gas-powered generator can be a viable option during a blackout. A dual-fuel generator gives you numerous benefits, like easier access and storage options for fuel. 

The EcoFlow dual-fuel Smart Generator gives the best of both worlds. When you combine it with a EcoFlow DELTA Pro Portable Power Station, you can do even more to save on fuel costs and prepare for any power outage that may come. 

Frequently Asked Questions

How much does it cost to run a dual fuel generator for 24 hours?

A generator like the EcoFlow Smart Generator uses about 0.3 gallons of gasoline per hour when operating at full capacity. If it were to run for 24 hours, it would consume about 7.2 gallons. At an average fuel cost of $3 per gallon, you’ll pay about $0.90 per hour. For 24 hours, that would cost about $22. If you use propane primarily, your fuel costs should be lower.

How much gas does it take to run a whole-house generator?

The amount of gasoline required to power an entire home depends on numerous factors — primarily your electricity consumption. If your home consumes the US average of around 30kWh of electricity per day, a 5kW gas generator running at 75% capacity can produce around 10kWh of electricity in 8 hours. Keep in mind, the maximum simultaneous output is 5kW. If you need to run appliances that consume more than 5kW in total at the same time, you’ll need to purchase a 10kW generator or higher. The average 5kW gas generator burns about 0.75 gallons an hour. If you run the generator for 8 hours a day at 0.75 capacity, you will consume about 6 gallons daily. 

Keep in mind that hybrid fossil-fuel/solar whole home generators will consume significantly less fuel and provide more energy savings in the long run. 

Is It Cheaper to Power a House With a Gas Generator?

No. The fuel costs of a gas generator are significantly higher than on-grid electricity or renewable energy solutions like solar. Using a gas generator to power your home is usually a short-term alternative for blackouts or locations without on-grid electricity rather than a long-term power solution.

EcoFlow is a portable power and renewable energy solutions company. Since its founding in 2017, EcoFlow has provided peace-of-mind power to customers in over 85 markets through its DELTA and RIVER product lines of portable power stations and eco-friendly accessories.

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