How to calculate gas cost
First find how many gallons the trip needs, then multiply by the price per gallon:
Gallons = Distance ÷ MPG • Cost = Gallons × Price
A 300-mile trip at 30 MPG uses 10 gallons; at $3.50 per gallon that's $35. Spread over the 300 miles, that's about 12 cents per mile.
Splitting the cost
Carpooling? Divide the total by everyone sharing the ride, including the driver:
Per person = Total cost ÷ People
That $35 trip split four ways is about $8.75 each. Enter your round-trip distance if you want the there-and-back total.
Frequently asked questions
How do I calculate the cost of gas for a trip?
Divide the trip distance by your fuel economy to find the gallons needed, then multiply by the price per gallon. A 300-mile trip in a car that gets 30 MPG uses 10 gallons; at $3.50 a gallon that is $35 in fuel.
How do I find my fuel economy (MPG)?
Fill the tank and note the odometer, drive until you refill, then divide the miles driven by the gallons it took to top off. For example, 300 miles on 10 gallons is 30 miles per gallon. Use a few fill-ups for a reliable average.
How do I split gas costs with passengers?
Divide the total fuel cost by the number of people sharing the ride, including the driver. A $35 trip split among 4 people is about $8.75 each. Enter the number of travelers and the calculator shows the per-person share.
Does this include a round trip?
Only if you enter the round-trip distance. The calculator uses whatever distance you provide, so double your one-way miles if you want the cost there and back.
What is a good cost per mile for fuel?
It depends on gas prices and your vehicle, but at $3.50 a gallon a 30-MPG car costs about 12 cents per mile in fuel, while a 20-MPG vehicle is closer to 18 cents. Cost per mile is a quick way to compare vehicles or routes.
Disclaimer: Real fuel use varies with driving style, terrain, traffic, load, and weather. Results are estimates for planning only.