Generator operating costs

How much does it cost to run a generator

Open notebook, pencil and calculator on a planning desk.

The short answer

How much does it cost to run a generator? Fuel cost is documented fuel use times your matching local price and run hours. Published watts alone do not supply a burn rate. Keep maintenance, delivery and other fees separate. Use actual fuel consumed at a stated load, then compare your own low and high inputs.

Last updated October 2026

What's covered9

Generator running cost has three parts: fuel, load and time. Each part changes the final number. This guide explains them with manufacturer data. It also shows how to turn that data into your own estimate.

Running cost is the fuel you burn multiplied by what that fuel costs where you live. Fuel burned depends on the exact model, the fuel type, the load and the hours. No single price fits every generator. Use documented fuel consumed and your matching price. The running cost calculator does the math for you.

Generator running cost data at a glance

The table lists manufacturer figures. Runtime appears only where the source gives it.

Model Fuel Rated or running output Runtime data Voltage
Honda EU2200i Gasoline 1800 W rated 3.2 h rated load, 8.1 h quarter load, 0.95 gal tank 120 V
Honda EU3000iS Gasoline 2800 W rated 6.9 h rated load, 19.6 h quarter load 120 V
Westinghouse WGen11500TFc Gasoline / propane / natural gas 11,500 W gasoline; 10,500 W propane; 9,500 W natural gas Gasoline: 19 h at 25% load, 9.5 h at 50% load 120/240 V
DuroMax XP13000HXT Gasoline / propane / natural gas 10,500 W gasoline; 10,000 W propane; 9,000 W natural gas Not listed here 120/240 V
Champion 201176 Gasoline / propane / natural gas 7250 W gasoline; 6525 W propane; 5875 W natural gas Not listed here 120/240 V
Westinghouse iGen2550DFc Gasoline / propane 1900 / 1700 W Not listed here 120 V
Generac Guardian 26 kW Propane / natural gas 26 / 22.5 kW Not listed here 240 V
KOHLER 20RCA Propane / natural gas 20 / 18 kW Not listed here 120/240 V option
Cummins RS20A Propane / natural gas 20 / 18 kW Not listed here 120/240 V
BLUETTI AC200L Battery 2400 W AC output 2048 Wh stored 120 V
Jackery Explorer 2000 v2 Battery 2200 W AC output 2042 Wh stored 120 V

Match your unit's label and manual revision before sizing loads. Starting watts do not promise a motor will start or state how long peak output lasts.

The three parts of generator running cost

Fuel is the first part. You buy gasoline by the gallon. Propane comes from a tank you refill. Natural gas comes through a utility line and is billed by the meter.

Load is the second part. Add the running watts of everything that will run at once. Call that total R. Compare R with the rated output for the fuel you will use.

Motors need extra watts to start. If one motor starts at a time, add its starting gap to R. The gap is its starting watts minus its running watts. Use the largest gap of any single item.

If motors may start together, add all their gaps. Do not add a full starting figure on top of the same item's running watts.

Time is the third part. It is the number of hours you plan to run. Oil, filters and other service follow your owner's manual. They sit outside this fuel math.

Worked example: how much does it cost to run a generator

This is illustrative arithmetic, not a model benchmark or current fuel price. Suppose documented fuel use is 0.4 to 0.6 gallons per hour. Suppose your entered price is $3 to $4 per gallon. Ten run hours use 4 to 6 gallons.

Fuel cost is $12 to $24. Your own source data may give a different result.

Keep the burn rate separate from nominal tank capacity. Honda publishes a 0.95-gallon tank and load-specific runtime for the EU2200i. Honda does not state the actual fuel used in each test. Dividing nominal tank size by those hours would add an unverified assumption.

Use a documented consumption rate or your own measured record instead.

The EIA gasoline update provides dated US and regional reference prices. It reported a US regular gasoline average of $4.354 per gallon for October 5, 2026. That is a dated aggregate, not your current local pump price. The series includes taxes.

A delivered-fuel quote may have different fees and scope.

Make the estimate match your planned run

Record the run hours you intend to supply. A generator does not need to run every hour of an outage if your plan allows breaks. That choice belongs to your household plan. Keep it separate from the arithmetic.

A ten-hour input means ten operating hours, not a whole calendar day.

Keep the load point with the consumption record. A quarter-load observation does not describe full-load use. Do not draw a straight fuel curve from one point. If your actual load is unknown, your fuel estimate is incomplete.

Collect a suitable observation before you rely on a precise budget.

Record the price unit too. A price per gallon cannot multiply a rate in pounds per hour. A propane refill price may exclude delivery or other charges. A natural-gas bill may use different billing units from the manual.

Resolve that unit difference before you calculate. The worksheet does not silently convert it.

Propane and natural gas generator running costs

Some listed models make less power on propane than on gasoline. The iGen2550DFc drops from 1900 W to 1700 W. The DuroMax, Champion 201176 and WGen11500TFc lose more on natural gas. These figures apply to these models only.

The listed standby units also rate lower on natural gas than on propane. Generac lists 26 kW on propane and 22.5 kW on natural gas. KOHLER and Cummins both list 20 kW on propane and 18 kW on natural gas.

Lower output matters for cost planning. If R is close to the propane or natural gas rating, the unit may not carry your load. Check the rating for your fuel before you size around it.

Only the Generac Guardian sheet gives propane and natural gas burn rates. So this guide cannot turn the other units' watts into fuel use. Electric watts do not tell you gas flow. Fuel pressure, flow and source voltage are separate checks in each product's own instructions.

Natural gas needs a suitable line at the site. Gas and electrical work belongs to licensed trades.

Battery power stations: energy, not fuel

Battery stations store energy in watt-hours. Watts measure power at one moment. Watt-hours measure energy over time. 1000 watt-hours equal 1 kilowatt-hour.

The BLUETTI AC200L stores 2048 Wh, or about 2.05 kWh. The Jackery Explorer 2000 v2 stores 2042 Wh. Both burn no fuel. BLUETTI lists solar and AC recharge for the AC200L.

Use measured wall energy for a recharge cost. Multiply the measured kWh by your dated electricity rate. Nameplate battery capacity is not the wall energy needed to recharge it. The starting charge level and charging losses matter.

This guide does not invent an efficiency value to fill that gap.

Runtime from a battery depends on stored energy and the load. A 1000 W load for one hour uses 1000 Wh. Once the stored energy runs out, you must recharge.

Safety limits that shape run time

CPSC says portable engine generators belong outdoors. Keep them at least 20 feet from homes, with exhaust pointed away. Never run one indoors or in a garage, even with the doors open.

CPSC also says to shut the engine down and let it cool before refueling. Each refill stops your run time. Never plug a generator into a wall outlet to backfeed the house. Use CO alarms, and get to fresh air if one sounds.

Standby units follow the clearances in their own manual and local rules. Battery stations follow their own product instructions.

Sources, method and limitations

Output, runtime and capacity figures come from manufacturer pages or brochures. Safety guidance comes from CPSC. Unit definitions come from the US Department of Energy style guide.

The worked example uses hypothetical inputs only. It demonstrates multiplication, not a measured fuel curve. Manufacturer runtime records retain their stated load and fuel. We do not derive consumption from nominal tank size when actual used fuel and the test endpoint are missing.

One model-specific example: the Generac Guardian 26 kW sheet lists 2.06 gallons of propane per hour at half load and 3.63 at full load. At EIA's $2.598 per gallon residential propane reference (October 5, 2026), that is about $5.35 to $9.43 an hour. Your price will differ. This guide does not test any generator. A model's output alone does not prove it fits your home or transfer equipment.

For installed standby budgets, Generac publishes an indicative US total of $8,000 to $16,000. That covers equipment, materials and installation. It is not a quote. See whole house generator cost for more.

To run your own numbers, use the generator running cost calculator. To estimate hours, use the generator run time calculator. To compare models, see the best generator for home guide.

How much does it cost to run a generator FAQs

Is there a standard cost per hour?

No. Cost per hour depends on the model, the fuel, the load and your local fuel price. Honda's EU2200i, for example, lasts 3.2 hours at rated load but 8.1 hours at quarter load. That difference changes fuel used per hour.

Enter your model's own data and local price in the calculator.

Does fuel type change available power?

On the listed models, yes. The Champion 201176 lists 7250 W on gasoline, 6525 W on propane and 5875 W on natural gas. The Generac 26 kW lists 26 kW on propane and 22.5 kW on natural gas. Check your exact model's rating for each fuel you plan to use.

How do I find gallons per hour?

Use the actual fuel consumed at a known load and endpoint, divided by the measured run hours. Nominal tank capacity is not the same datum. Honda lists tank size and runtime for the EU2200i, but Honda does not state the fuel used in each test. A burn rate based on those two values alone would be assumed.

How is battery cost measured?

Battery stations store energy in watt-hours. Recharge cost needs the wall energy drawn during a recharge, measured in kWh, and your electricity rate. Nominal pack capacity alone does not supply wall energy. Starting charge level and losses matter.

Use a measured charging record rather than an invented efficiency percentage.

Primary documents

How much does it cost to run a generator Verdict

How much does it cost to run a generator results depend on the exact inputs below.

Running cost is documented fuel use times your matching local price. You also need the hours you plan to run. A nominal tank size and a runtime claim do not establish actual consumption by themselves. Keep that assumption unresolved until the source or a measured record supplies it.

If you use propane or natural gas, check that fuel's rating against your total load. If you use a battery station, plan in watt-hours and kWh. Then use the linked calculators with your exact figures.

Continue your backup plan

Compare the backup options

With your load and cost limits in hand, compare home backup options. Match the listed limits to your figures before choosing a model or planning an installation.