How the fuel cost calculator works
The trip cost depends on three numbers: the distance, the vehicle's fuel efficiency, and the price of fuel. This tool estimates the fuel needed, the total trip cost, and the cost per mile and per kilometer.
Example
You drive 250 miles in a car that gets 28 MPG, and gas costs $3.85 per gallon. Fuel needed = 250 ÷ 28 = 8.93 gallons. Trip cost = 8.93 × 3.85 = $34.38, about $0.14 per mile.
Notes and assumptions
- Fuel efficiency is entered in miles per gallon (MPG). To use liters per 100 km, convert to MPG first or enter the equivalent value.
- The calculator uses exact decimal arithmetic; displayed gallons are rounded to four decimal places.
- Fuel efficiency must be greater than zero because dividing by zero is undefined.
- The result is an estimate. Real-world consumption varies with speed, traffic, weather, vehicle load, and driving style.
- Cost per mile and per kilometer help you compare the efficiency of different vehicles or routes before a trip.
Frequently asked questions
How do I calculate fuel cost for a round trip?
Enter the round-trip distance in the distance field. For a 250-mile each-way trip, enter 500 miles.
How do I convert MPG to liters per 100 km?
L/100 km = 235.2146 ÷ MPG. A car that gets 28 MPG uses about 8.4 L/100 km.
Does this account for city vs. highway driving?
No. Use your average real-world MPG for the most accurate estimate, since highway driving is usually more efficient than city driving.
How can I lower my fuel cost?
Improve MPG by keeping tires inflated, reducing speed, and removing extra weight. A small efficiency gain adds up over a long trip.