Everyday
Fuel Cost Calculator
Know what a drive costs before you leave. Enter the distance, your car's fuel economy, and the price at the pump — get the total fuel cost, gallons you'll burn, and a fair per-person split for road trips.
Trip fuel cost
$28.00
Gas needed
8 gal
Cost per person
$28.00
Cost per mile
$0.12
Fuel is only part of the true cost of driving — the IRS mileage rate (which also covers wear, maintenance, and depreciation) is roughly double the fuel-only figure.
How it works
The math is two steps: distance divided by your car's mpg gives gallons burned, and gallons times the pump price gives the cost. A 240-mile trip in a 30-mpg car at $3.50/gal burns 8 gallons and costs $28.
Real-world fuel economy is usually 10–20% worse than the window sticker, especially with highway speeds over 70 mph, a loaded car, or a roof box. If you want a conservative estimate, knock a few mpg off the official figure.
Fuel is only about half the true cost of driving. The IRS standard mileage rate — designed to cover gas plus wear, tires, maintenance, and depreciation — is roughly double the typical fuel-only cost per mile. Keep that in mind when splitting costs with passengers on a long trip.
Gallons = distance / mpg
Fuel cost = gallons × price per gallon
Per person = fuel cost / passengers
Example: 240 mi / 30 mpg = 8 gal × $3.50 = $28.00 → $14.00 each (2 people)Frequently asked questions
How do I find my car's real mpg?
Fill the tank completely, reset the trip odometer, drive normally, then refill. Miles driven divided by gallons added is your true mpg. Do it over two or three tanks for a reliable average — trip computers often read 5–10% optimistic.
How much should passengers chip in for gas?
The simple fair split is the fuel cost divided by everyone in the car, driver included. For long trips, some groups add a bit extra for wear on the driver's car — the IRS mileage rate is a reasonable ceiling for what the full cost really is.
Does driving speed really affect fuel cost?
Significantly. Aerodynamic drag grows with the square of speed — most cars lose 15–25% efficiency at 80 mph versus 65 mph. On a long highway trip, slowing down 10 mph can save several dollars per tank.
How do I estimate cost for an electric car?
Same idea with different units: kWh per mile times electricity price. A typical EV uses about 0.28 kWh/mile; at $0.15/kWh that's roughly 4 cents a mile — versus about 12 cents a mile for a 30-mpg gas car at $3.50/gal.
Is it cheaper to drive or fly?
For solo travelers on long routes, flying often wins once you count fuel both ways. For families, driving usually wins because the car's cost barely changes with more passengers while airfare multiplies per seat. Run the fuel number here and compare it to total airfare.