Gas Cost Calculator
What does a trip cost in gas? Calculate gas cost, gallons used and cost per person from distance (miles), MPG and gas price — including carpooling and round trips.
Key facts
- Method: miles ÷ MPG = gallons used, × gas price = cost. Example: 100 mi at 27 MPG = 3.7 gallons, at $3.85/gal about $14.26.
- Price guide: the US average for regular is about $3.85/gal (AAA); 27 MPG is the EPA new-vehicle average — best enter the price from your last fill-up and your vehicle’s MPG.
- A round trip counts double; carpooling splits the cost: with 4 people each pays a quarter — $14.26 becomes about $3.56 per head.
FAQ
- How do I calculate the gas cost of a trip?
- Miles divided by MPG gives the gallons used. Times the gas price ($/gal) gives the cost. Example: 100 mi ÷ 27 MPG = 3.7 gallons, at $3.85/gal about $14.26. A round trip counts double the distance.
- Which gas price and MPG should I enter?
- Best use the price from your last fill-up and your vehicle’s real MPG. The defaults are $3.85/gal (AAA US average) and 27 MPG (EPA new-vehicle average). Prices vary daily and by state.
- How much does carpooling save?
- The gas cost stays the same but is split by the number of people. With 4 people each pays a quarter. Enter the number of people to see the cost per person.