How the fuel cost is calculated
The calculator works out how much fuel the trip needs, then multiplies it by the price you enter:
Fuel cost = distance ÷ fuel efficiency × fuel price
For example, a 300-mile trip in a car that does 30 miles per gallon needs 10 gallons. At $4.00 a gallon, that is $40. In metric units, a 500 km trip in a car that uses 6 litres per 100 km needs 30 litres; at €1.80 a litre, that is €54. You can mix units freely: enter the distance in km, the efficiency in MPG and the price per litre, and the calculator converts everything for you.
The CO₂ figure is the carbon dioxide released by burning that fuel, using the US Environmental Protection Agency's factors of 8,887 grams per gallon of gasoline and 10,180 grams per gallon of diesel.
US gas prices this week
In the week of 19 October 2026, a gallon of regular gasoline cost $4.28 on average in the United States ($1.13 a litre), and a gallon of diesel cost $6.28 ($1.66 a litre). A year earlier, regular gasoline averaged $3.02.
Source: U.S. Energy Information Administration, weekly retail prices, all formulations, including taxes. EIA publishes new prices every week; this page updates the next day.
US gas prices by year
| Year | Regular gasoline | Diesel |
|---|---|---|
| 2026 (to date) | $3.86 | $5.10 |
| 2025 | $3.10 | $3.66 |
| 2024 | $3.30 | $3.76 |
| 2023 | $3.52 | $4.21 |
| 2022 | $3.95 | $4.99 |
| 2021 | $3.01 | $3.29 |
| 2020 | $2.17 | $2.55 |
| 2019 | $2.60 | $3.06 |
| 2018 | $2.72 | $3.18 |
| 2017 | $2.41 | $2.65 |
About the historical chart
Tick "See historical data" to see how far the money for your trip would have taken you in each week of the past 10 years, in the same car. It uses the weekly US average price from the U.S. Energy Information Administration: when gas was cheaper, the same money bought more fuel and went further. If you use another currency or your own price, the chart applies the same changes in the US average price to your trip, so treat it as a guide to the trend rather than an exact figure for your country.
Questions
What is the average gas price in the US today?
In the week of 19 October 2026, regular gasoline averaged $4.28 a gallon across the United States, according to the U.S. Energy Information Administration. Over the past 10 years, the weekly average has ranged from $1.77 (week of 27 April 2020) to $5.01 (week of 13 June 2022).
How much does it cost to drive 100 miles?
With a car that does 30 miles per gallon and gasoline at the US average of $4.28, 100 miles uses 3.33 gallons and costs about $14.28. In metric terms, a car using 7 litres per 100 km costs about $7.92 per 100 km at the same price. Enter your own car and price above for an exact figure.
How do I convert MPG to litres per 100 km?
Divide 235.21 by the miles per gallon (US). For example, 30 MPG is 235.21 ÷ 30 = 7.8 litres per 100 km. For UK (imperial) gallons, divide 282.48 by the MPG instead. The calculator does this for you when you change the unit.
Which currencies can I use?
Any of the currencies in the list. Choose yours and type the price you pay at the pump, per litre or per gallon. The US average price is only filled in automatically for US dollars.
Results are estimates: real fuel use depends on speed, traffic, load and weather. US prices: U.S. Energy Information Administration. See how this site works.