Fuel Cost Calculator
Fuel cost calculator: trip fuel cost from distance, MPG and gas price Free, no sign-up, and it runs in your browser.
Dedicated page: /en/fuel-cost-calculator
Default checked 10 Nov 2026: $4.01 (AAA national average for regular, 9 Nov 2026). Enter your local price. Check the current value here.
US average residential electricity is about $0.17 per kWh (EIA). Enter your own rate if you know it.
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Quick answer
A fuel cost calculator works out what a trip costs in gas. Enter the distance, your miles per gallon and the price per gallon, and it shows the gallons needed, the total fuel cost, the cost per mile, the split between passengers, the monthly and yearly totals for repeated trips, and how an electric car compares.
About this Fuel Cost Calculator
Fuel cost calculator: trip fuel cost from distance, MPG and gas price It is one of the Car and Travel on ToolUstad, and like every tool here it runs entirely in your browser: nothing you type, paste or open is uploaded to a server, and there is no sign-up or usage limit.
What is a fuel cost calculator?
A fuel cost calculator turns three numbers into the answer that decides a trip budget: how far, how efficiently, and what fuel costs. The formula has two steps. Gallons is distance divided by MPG: 300 miles at 28 MPG needs 10.71 gallons. Cost is gallons times the price per gallon: at $4.01 a gallon, that is $42.96, or $0.14 a mile. As a round trip the distance doubles to 600 miles and the cost to $85.93. Make the same trip 4 times a month and it costs $171.86 a month, $2,062.29 a year.
The price you enter matters as much as the MPG. The AAA national average for regular gasoline was $4.01 a gallon as of 9 Nov 2026, down from $4.37 a month earlier and well above the $3.06 of a year earlier. Diesel was $6.17. State prices spread widely: California averaged about $5.83, while North Carolina was the cheapest at about $3.38. The calculator defaults to the national average and lets you enter your local price.
Why trips cost more than the sticker says
Real-world MPG usually runs 10 to 20 percent below the rated figure, because the rating comes from a standardised lab cycle and real driving adds highway speed, air conditioning, stop-start traffic and cold starts. A car rated at 32 MPG combined may really do 28 MPG, which turns a $37.50 trip into $42.96. The comparison table runs the same trip at 20 to 50 MPG, so you can see the cost of every efficiency level at your price.
Electric cars and CO2
The EV comparison runs the same trip on electricity. An EV at 3.5 miles per kWh needs 85.71 kWh for 300 miles, and at $0.17 per kWh, the US average residential rate, that costs $14.57, against $42.96 for gasoline. The calculator also reports CO2: burning a gallon of gasoline emits about 8.887 kg of CO2, according to the US EPA, so the 300-mile trip emits about 95.2 kg. Diesel emits about 10.18 kg per gallon.
Best practices
- Use your measured MPG: fill the tank, drive, fill it again, and divide miles by gallons.
- Enter your local price: state averages spread from about $3.38 to $5.83 a gallon, so the national average can be a dollar out.
Common mistakes to avoid
- Budgeting from the EPA rating instead of real MPG, and undershooting by 10 to 20 percent.
- Forgetting tolls, parking and food, which the road trip cost calculator on this site adds.
Who is the fuel cost calculator for?
Drivers pricing a trip, commuters working out a monthly fuel budget, and buyers comparing two cars or a gasoline car with an EV.
Current value, checked 10 Nov 2026: the default gas price is $4.01, the AAA national average for regular gasoline as of 9 Nov 2026, from the AAA Fuel Prices page. The price box is an optional override. Check the current value here.
Learn: how to use the Fuel Cost Calculator
- Enter the trip distance in miles and your fuel economy in MPG.
- Pick the fuel type, or enter your local gas price directly. The default is the AAA national average.
- Choose one way or round trip, and how many passengers share the cost.
- Set how many times a month you make the same trip, and a second car MPG to compare.
- Read the gallons, the cost, the cost per mile, the monthly and annual totals, and the EV comparison.
Features
- Distance, MPG and gas price to gallons and total cost
- Four fuel types with AAA-based default prices, plus any price you enter
- Round-trip doubling and cost split between passengers
- Monthly and annual fuel budget from trips per month
- Car A vs car B comparison with the saving per trip
- EV comparison with miles per kWh and your electricity price, plus CO2
Worked example
A 300-mile trip at 28 MPG needs 10.71 gallons. At $4.01 a gallon that costs $42.96, or $0.14 a mile, and emits about 95.2 kg of CO2. As a round trip it is $85.93. Making the same trip 4 times a month costs $171.86 a month and $2,062.29 a year. A 35 MPG car costs $34.37 for the same trip, saving $8.59. An EV at 3.5 miles per kWh and $0.17 per kWh does the trip for $14.57.
Frequently asked questions
How do I calculate fuel cost for a trip?
Divide the distance by your MPG to get the gallons, then multiply by the price per gallon. A 300-mile trip at 28 MPG needs 10.71 gallons, and at $4.01 a gallon that is $42.96. Use your real MPG, not the EPA rating, for an accurate figure.
What is the current average gas price?
The AAA national average for regular gasoline was $4.01 a gallon as of 9 Nov 2026, down from $4.37 a month earlier and above the $3.06 of a year earlier. Diesel was $6.17.
Why does my trip cost more than the calculator says?
Real-world MPG usually runs 10 to 20 percent below the rated figure, because of highway speed, air conditioning and stop-start driving. Measure your real MPG with the MPG calculator on this site and use that number.
Is premium gas worth it?
Only if your car requires it. Premium costs about $0.60 a gallon more than regular, and most cars designed for regular gain nothing from it. Check the fuel door or the manual: required means required, recommended means regular still works.
How much does an EV save on the same trip?
An EV at 3.5 miles per kWh and $0.17 per kWh costs about $0.05 a mile, against $0.14 a mile for a 28 MPG car at $4.01 a gallon. On a 300-mile trip that is $14.57 against $42.96.
How much CO2 does a trip emit?
Burning a gallon of gasoline emits about 8.887 kg of CO2, according to the US EPA. A 300-mile trip at 28 MPG burns 10.71 gallons, so about 95.2 kg. Diesel emits about 10.18 kg per gallon.
Should I use the rated MPG or my measured MPG?
Your measured MPG. The rated figure comes from a lab cycle, and most drivers see 10 to 20 percent less in real driving. Fill the tank, drive, fill it again, and divide the miles by the gallons for your real number.
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