How do you calculate gas cost for a trip?

Electrical & MechanicalFuel Economy Conversion

Fuel Consumption & Road Trip Cost Calculator

Calculate total road trip fuel consumption, cost per mile, and convert instantly between US Miles Per Gallon (MPG) and Liters per 100 km.

Electrical & Mechanical Field StandardsFuel Economy Conversion

Engineering formulations calibrated to IPC, UPC & NEC specificationsSub-Zero Cold Climate Tolerances

Quick Summary & Key Answer

To calculate road trip fuel cost, divide total distance by your vehicle's MPG to determine gallons needed, then multiply by the price of gas. Driving 350 miles at 24 MPG with gas at $3.85/gallon requires 14.6 gallons, costing exactly $56.15 ($0.16 per mile).

To convert US MPG to Liters/100km: divide 235.215 by MPG.
Aggressive acceleration and speeding above 70 MPH lowers gas mileage by 15-30%.
Under-inflated tires increase rolling resistance, reducing fuel economy by up to 3%.

Interactive Calculator

Adjust inputs for real-time results

Trip Distancemiles

miles

Fuel Economy (MPG)MPG

MPG

Gas Price per Gallon$/gallon

$/gallon

Calculated OutputTrip Fuel Calculated

Total Estimated Fuel Cost

$56.15$

Total Fuel Required: 14.6 Gallons
Cost Per Mile Driven: $0.160 / mile
Metric Fuel Economy: 9.8 L/100km
Trip Distance in Kilometers: 563 km

Note: Highway aerodynamic drag increases substantially above 65 MPH, reducing real-world fuel economy by 10% to 15%.

Maximizing Vehicle MPG

Maintaining proper tire pressure and using cruise control on highway stretches can save 10% to 20% on road trip fuel.

Frequently Asked Questions

Common questions regarding this calculation and code compliance

Divide trip miles by your vehicle's MPG to get total gallons, then multiply by the current price of gas.