How Much Gas Does a Road Trip Cost?
Divide trip miles by MPG, multiply by price per gallon, then add a buffer for traffic and detours.
By Gas Tracker Editorial · Published 2026-02-05 · Updated 2026-03-01
Short answer
Trip fuel cost ≈ (trip miles ÷ MPG) × average $/gal for the route.
Example
450 miles at 28 MPG and $3.50/gal → 16.1 gal × $3.50 ≈ $56 in fuel (plus snacks).
Try the Trip Fuel Cost Calculator.
Use your real MPG
Highway MPG from a recent road trip beats the window sticker for planning.
After the trip
Log fill-ups in Gas Tracker AI to compare estimate vs actual spend.