Gas Trip Calculator

The Real Cost of Driving

Gas is the most visible cost of driving but it is far from the only one. The IRS standard mileage rate for 2026 is 70 cents per mile, which accounts for gas, depreciation, maintenance, insurance, and tires. A 350-mile trip at the IRS rate costs $245 in total vehicle expense — versus roughly $43 in gas alone at 28 MPG and $3.45/gallon. The gas-only calculation is what you pay at the pump, but the true cost includes the wear you are putting on the vehicle.

This distinction matters when comparing driving to flying. A 350-mile flight might cost $150, and gas for the drive is only $43 — driving looks cheaper. But add depreciation ($0.25/mile = $87.50), maintenance and tires ($0.09/mile = $31.50), and 5-6 hours of your time, and flying often wins on total cost for distances over 300 miles. For shorter trips or when traveling with multiple passengers who would each need a plane ticket, driving wins decisively.

How to Improve Your MPG

Your actual fuel efficiency varies 20-30% depending on how you drive. Highway driving at 55-65 mph is the sweet spot for most vehicles — fuel efficiency drops roughly 7% for every 5 mph above 65. Aggressive acceleration and braking reduces MPG by 15-30% compared to smooth driving. Proper tire inflation alone affects fuel economy by 3-5%; most cars lose 1 PSI per month naturally, so checking monthly is worth the 2 minutes.

Cruise control on flat highways improves efficiency by 5-7% by eliminating the micro-accelerations that human drivers unconsciously make. Air conditioning reduces MPG by 3-10% depending on the system and outside temperature — but at highway speeds, opening windows creates enough drag to cancel out the AC savings. The breakeven point is roughly 45 mph: below that, open windows; above that, use AC.

EV Road Trip Comparison

Electric vehicles change the math significantly. A Tesla Model 3 uses roughly 25 kWh per 100 miles. At home charging rates of $0.13/kWh, that is $3.25 per 100 miles. At Supercharger rates of $0.35/kWh, it is $8.75 per 100 miles. Compare that to a gas car at 28 MPG and $3.45/gallon: $12.32 per 100 miles. Even at Supercharger prices, the EV costs 29% less in fuel. At home charging rates, it costs 74% less.

How do I calculate gas cost for a trip?

Distance (miles) ÷ fuel efficiency (MPG) × gas price per gallon = total gas cost. For a 350-mile trip at 28 MPG with $3.45 gas: 350 ÷ 28 × $3.45 = $43.13. Double for a round trip.

What is the average MPG?

The average new car in 2026 gets approximately 28-30 MPG combined. SUVs average 24-26 MPG. Trucks average 20-23 MPG. Hybrids average 45-55 MPG. Your actual MPG is on the window sticker or in your owner's manual — check the "combined" rating for the most realistic estimate.

Is it cheaper to drive or fly?

For solo travelers, flying is often cheaper for distances over 300 miles when you factor in time, depreciation, and maintenance. For 2+ passengers, driving is almost always cheaper because you only pay for gas once regardless of passenger count. For a family of 4, driving saves $300-800 on flights for trips under 500 miles.