Gasoline / Fuel Cost & Trip Distance Calculator

Trip distance, fuel efficiency, and price, combined

A 320-mile trip at 28 MPG and $3.69 per gallon requires 11.43 gallons (320 / 28) and costs $42.17 total -- or $0.1318 per mile, a useful figure for comparing against other per-mile costs like a mileage reimbursement rate.

Cost per mile ($0.1318) is calculated two equivalent ways -- total cost divided by total miles, or simply gas price divided by MPG ($3.69 / 28 = $0.1318) -- both arrive at the same figure, which is a handy sanity check if you're calculating this by hand.

This is a direct, proportional relationship: doubling trip distance to 640 miles at the same MPG and gas price would exactly double both gallons needed and total cost, since the underlying per-mile cost rate doesn't change with distance.

Why real-world fuel cost often runs higher than this estimate

Highway sticker MPG is optimistic. Idling and wind are omitted. EPA-estimated or manufacturer 'sticker' MPG figures are typically measured under controlled, favorable conditions -- real-world driving (city stop-and-go traffic, hills, cold weather, headwinds, and idling in traffic) commonly delivers somewhat lower fuel economy than the advertised rating, especially for around-town driving versus steady highway cruising.

This also doesn't account for fluctuating fuel prices along a longer route -- gas prices vary by region and even by specific station, so a long road trip's actual average price per gallon paid could differ meaningfully from a single price entered here.

For a more accurate real-world estimate, using your vehicle's actual observed MPG (calculated from real fill-ups and mileage, rather than the sticker rating) as the input here would produce a more reliable cost projection.

Related trip-cost and travel tools

If the trip is being made in an electric vehicle instead of a gas-powered one, the EV Charging Time & Cost Estimator is the equivalent cost calculation for that different fuel type.

If the trip involves renting a moving truck or similar vehicle, the Moving Truck Rental Cost Estimator is a related trip-planning tool.

Frequently Asked Questions (FAQ)