How do I find my car's MPG?

Check fueleconomy.gov or divide miles driven by gallons used at your last fill-up.

Does speed affect fuel cost?

Yes, fuel efficiency drops significantly above 50 mph due to wind resistance.

Use the same formula but with diesel price and diesel MPG rating.

Fuel cost depends on three factors: distance, vehicle fuel efficiency, and fuel price. Dividing distance by MPG gives gallons needed.

Fuel Cost = (Distance / MPG) x Price per Gallon

Where:

DDistance — Trip distance in miles

MPGFuel Efficiency — Miles per gallon of your vehicle

PPrice — Cost per gallon of fuel

Here's how to calculate fuel cost step by step:

1Find your MPG: Check your vehicle specs or calculate from recent fill-ups.
2Determine distance: Use a map tool to find the trip distance in miles.
3Calculate cost: Divide distance by MPG, then multiply by fuel price per gallon.

Following these 3 steps gives you the final fuel cost value.

A 300-mile trip in a car getting 25 MPG with gas at $3.50/gallon costs (300/25) x 3.50 = $42 one way.

Fuel cost estimation helps budget road trips, compare driving vs flying, and evaluate vehicle efficiency.

City MPG is typically 20-30% lower than highway MPG.

Double the one-way distance for round-trip fuel cost.

Gas prices differ by region; check prices along your route.