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Fuel Cost Calculator

Trip fuel cost from distance and MPG.

Result

Fuel cost

$14.00

Fuel needed
4gal
How it’s worked out
  1. Fuel needed = distance ÷ MPG = 100 ÷ 25 = 4 gal
  2. Cost = 4 × $3.50 = $14.00

Fuel Cost Calculator

What this calculator does

This calculator estimates the total fuel cost for a trip based on the distance, your vehicle's fuel efficiency (miles per gallon or liters per 100 km), and the current price of fuel. It helps you budget for road trips, compare driving costs against flying or taking a train, and evaluate the fuel expense of a daily commute.

Gas prices fluctuate constantly, and fuel is often the largest variable cost of driving. Whether you are planning a cross-country road trip, estimating your monthly commute expense, or deciding between two vehicles with different MPG ratings, this calculator gives you a concrete dollar figure so you can make informed decisions.

You can also use it to split fuel costs among passengers for carpooling, making it a practical tool for group travel.

How to use it

  1. Enter the trip distance in miles (or km).
  2. Enter your vehicle's fuel efficiency in MPG (or L/100 km).
  3. Enter the fuel price per gallon (or per liter).
  4. Optionally enter the number of passengers to split costs.
  5. Review the total fuel cost, gallons needed, and cost per person.

Formulas used

  • Gallons needed = Distance / MPG Example: 450 miles / 28 MPG = 16.07 gallons

  • Total fuel cost = Gallons needed × Price per gallon Example: 16.07 × $3.50 = $56.25

  • Cost per person = Total fuel cost / Number of passengers Example: $56.25 / 3 = $18.75 each

  • Metric version: Liters needed = (Distance in km × L/100 km) / 100 Total cost = Liters × Price per liter

Examples

Example 1 — Weekend road trip: Distance = 320 miles round trip. Vehicle = 30 MPG. Gas = $3.40/gallon. Fuel needed = 10.67 gal. Cost = $36.27.

Example 2 — Daily commute (monthly): Distance = 25 miles each way × 2 × 22 work days = 1,100 miles/month. Vehicle = 26 MPG. Gas = $3.60. Fuel = 42.3 gal. Monthly cost = $152.31.

Example 3 — Cross-country trip with carpool: Distance = 2,800 miles. SUV at 22 MPG. Gas = $3.50. 4 passengers. Fuel = 127.3 gal. Total cost = $445.45. Per person = $111.36.

Tips and common mistakes

  • Use your real-world MPG, not the EPA estimate. Highway driving, city driving, speed, A/C usage, tire pressure, and cargo weight all affect actual fuel efficiency. Check your trip computer or calculate it manually (miles driven / gallons filled).
  • Highway vs. city MPG matters. A car rated 25 city / 33 highway will perform very differently on a local errand run versus an interstate trip. Use the appropriate figure.
  • Account for price variation. Gas prices can vary by $0.50 or more between states or even between neighborhoods. Apps like GasBuddy can help you plan fuel stops along cheaper routes.
  • Idling burns fuel. Sitting in traffic, warming up the car, or waiting in drive-throughs adds fuel consumption that the calculator does not account for. Add 5–10% for heavy city driving.
  • Compare against alternatives. A 500-mile trip for one person at $80 in gas might seem cheap until you factor in wear and tear ($0.10–0.15/mile), tolls, and time. A $120 flight might be the better deal.
  • Electric vehicles have a different cost model (kWh per mile × electricity rate). This calculator is designed for gasoline and diesel vehicles.

Common questions

How do I get my car's MPG?

Check your owner's manual, or track miles and gallons over a few fill-ups and divide miles by gallons.

Does this work for electric vehicles?

For EVs, use miles per gallon equivalent (MPGe) and the cost per "gallon" of electricity if your provider gives it, or estimate from kWh and local rates.