Road Trip Cost Calculator Guide: Fuel Cost Explained
How to work out a road trip's total fuel cost from distance, fuel economy, and gas price, plus how splitting the cost between passengers works.
A road trip's fuel cost comes down to two questions: how many gallons will the trip take, and how much does a gallon cost right now?
The formula
Gallons needed = total distance ÷ MPG. Total cost = gallons needed × price per gallon. That's the whole calculation — everything else (round trip doubling, splitting between passengers) is just a variation on those two steps.
Worked example
A 600-mile round trip in a car averaging 30 MPG: 600 ÷ 30 = 20 gallons. At $3.60 a gallon, that's 20 × $3.60 = $72.00 total, or $18 each if four people are splitting it.
What this doesn't include
Fuel is the one cost that scales predictably with distance, but it's rarely the only cost of a trip — tolls, food, lodging, and parking add up separately and vary too much by route and travel style to estimate from distance alone.
The Road Trip Cost Calculator runs this instantly for any distance, vehicle, and group size.