Skip to content

Data updated 2026-10-26 · Source: EIA

GasPrices.cyou

Free calculator

Gas Cost Calculator

Enter the distance, your real-world fuel economy, and the price you actually pay. The calculator returns gallons burned, total fuel cost, cost per mile, and cost per person.

Price default: U.S. average, week ending 2026-10-26. Change it to your state or local price for a better estimate.

Estimated fuel cost

$0.00

Gallons needed
0.0
Cost per mile
$0.000
Cost per person
$0.00
Fuel per 100 miles
0.0 gal
Use your state price →

How to use the gas cost calculator

  1. Enter the one-way distance in miles. If you are driving there and back, tick the round trip box.
  2. Enter your car's real fuel economy. The EPA combined number is a fine starting point; use our MPG calculator if you want the true figure.
  3. Enter the price you actually pay. The default is the national average — for a real budget, use your state average or the price at the station you use.
  4. Add the number of people sharing the cost if you are splitting fuel with passengers.

The formula

Fuel cost = (distance ÷ MPG) × price per gallon. Gallons are distance divided by miles per gallon; cost is gallons multiplied by the pump price. Cost per mile is simply price divided by MPG, which is why a car that gets 35 MPG costs about 12 cents a mile at $4.27 a gallon, while a 15 MPG truck costs about 28 cents.

A worked example

A 300-mile drive at 28 MPG needs 10.7 gallons. At the current U.S. average of $4.269 per gallon, that is $45.73 in fuel. If four people split the ride, each pays about $11.43. The same trip in a 20 MPG SUV needs 15 gallons and costs $64.04 — a difference of $18.31 for one drive.

What the estimate does not include

  • Tolls and parking. In many metros these cost more than the fuel.
  • Wear and tear. Tires, brakes, and oil changes add roughly 5 to 10 cents per mile for a typical car.
  • Price changes. A road trip planned weeks ahead should carry a 10 to 15 percent buffer.
  • Cold starts and idling. Short trips in winter can burn 20 to 30 percent more fuel than the EPA rating.

Get a more accurate number in 30 seconds

Open your state page, copy the current average into the price field, and rerun the calculation. If your route crosses several states, use the highest state price along the route — fuel purchased at the most expensive point determines the worst case. For a multi-stop trip, the road trip fuel budget handles separate legs.

Frequently asked questions

How do you calculate the gas cost of a trip?

Divide the trip distance by your car’s miles per gallon to get the number of gallons, then multiply by the price per gallon. For a 300-mile trip at 28 MPG and $4.27 per gallon: 300 ÷ 28 = 10.7 gallons, and 10.7 × 4.27 = $45.73.

What MPG should I enter?

Start with the EPA combined rating for your vehicle, then subtract 15 to 20 percent if most of your driving is city traffic, air-conditioned, or loaded with passengers and cargo. Highway trips in mild weather often beat the EPA estimate. If you track odometer readings and gallons at fill-up, use our MPG calculator to get your real number.

Does this calculator include tolls, parking, or maintenance?

No. It covers fuel only. Tolls, parking, food, lodging, and wear items such as tires and oil changes are separate. For a full road trip budget, add those costs to the fuel number, and consider a 10 to 15 percent buffer for price changes between planning and departure.

Why is my actual fuel cost higher than the estimate?

The three most common reasons are driving faster than 65 MPH, heavy stop-and-go traffic, and extra load. Aerodynamic drag rises with the square of speed, so a 75 MPH highway trip can burn 15 to 20 percent more fuel than the same trip at 65 MPH.