Trip Gas Cost Calculator
Planning a road trip or just wondering what your commute really costs? Enter distance, fuel economy, and gas price to see gallons, fuel cost, tolls, and cost per mile.
How to use this calculator
- Enter trip distance.
- Enter vehicle fuel economy.
- Enter gas price.
- Enter tolls (round trip).
- Your results appear instantly below and update as you change the numbers.
How this calculator works
Divide miles by MPG to get gallons, multiply by the gas price, and add tolls. Worked example: 300 miles at 30 MPG uses 10 gallons; at $3.50 a gallon that is $35 of gas — about 11.7¢ per mile, or $40 with $5 of tolls.
Frequently asked questions
How do I estimate real-world MPG?
The EPA sticker number is optimistic. City driving, hills, roof racks, AC, cold starts, and towing can cut it 10–20%. Use your car's trip computer average, or the EPA highway number for long trips.
How much does a cross-country trip cost in gas?
A 2,900-mile coast-to-coast drive at 30 MPG uses about 97 gallons — roughly $340 at $3.50 a gallon. At 20 MPG (SUV/truck) it climbs to about $510.
Is an EV cheaper per mile?
Usually yes: an EV at 3.5 miles/kWh and $0.15/kWh home charging costs about 4.3¢ per mile, versus 11.7¢ for a 30 MPG gas car. Fast-charging on the road is closer to 12–18¢ per mile, narrowing the gap.
What is the cheapest way to drive long distance?
Keep tires inflated, drive 60–65 mph instead of 75 (highway MPG peaks around 60), remove roof racks, use cruise control, and combine errands. Each can add 2–10% fuel efficiency.
Disclaimer: Results are estimates for general information only and do not constitute financial, tax, or legal advice. Figures reflect 2026 rules and may change. Always confirm current limits and consult a qualified professional before making decisions. Official figures: IRS.gov · 2026 limits per IRS tax inflation adjustments.