Fuel Cost Calculator

How to use this tool

Choose a unit system. Select Imperial (miles and MPG) or Metric (kilometers and L/100km). Switching systems converts distance and fuel economy and clears the pump price so you can enter the local price for that unit.
Enter trip details. Enter the one-way distance, your vehicle's fuel economy, and the current local fuel price. Select Round trip to double the one-way distance for the estimate.
Optionally split the cost. Enter the number of passengers to see the cost per person.
Read the results. The calculator shows total trip distance, fuel needed, total fuel cost, and fuel-only cost per mile or kilometer. A cost-per-person row appears when more than one person is sharing the trip.

How to calculate fuel cost for a trip

For an Imperial estimate, divide distance in miles by miles per gallon to find gallons needed, then multiply by your local price per gallon. For Metric, multiply kilometers by liters per 100 kilometers and divide by 100 to find liters, then multiply by the local price per liter. The calculator also shows fuel-only cost per mile or kilometer. These estimates cover fuel only; they do not include tolls, parking, maintenance, or other trip expenses.

Enter the one-way distance. Select Round trip when you will return along the same distance; the estimate doubles the entered distance without changing the one-way value in the field. The results show the total distance used for the calculation. If you already entered both directions, leave One way selected to avoid counting the return twice.

When you switch between Imperial and Metric, distance and fuel economy are converted while your passenger count and trip type stay selected. The pump-price field is cleared because a price per gallon and a price per liter reflect different local markets. Re-enter the current pump price for the selected unit. The currency symbol follows the site's currency preference; it formats the amount but does not exchange or convert a market's fuel price.

Common fuel cost examples

These examples use one-way distances and the listed local pump prices. A round trip doubles the distance, fuel use, and fuel cost. If more than one person shares the trip, the calculator divides the total fuel cost equally and adds a per-person result; with one person, the total is already the per-person cost, so that extra row is hidden.

Distance	MPG	Price/gal	Total cost
100 mi	25	$3.50	$14.00
300 mi	30	$3.50	$35.00
500 mi	35	$3.50	$50.00
1,000 mi	40	$3.50	$87.50
200 km	8 L/100km	$1.60/L	$25.60
500 km	7 L/100km	$1.60/L	$56.00

MPG vs L/100km

Miles per gallon (MPG) is used in the United States and United Kingdom. A higher MPG means better fuel economy. Liters per 100 kilometers (L/100km) is used in Canada, Europe, and Australia; a lower number means better economy. The conversion is L/100km = 235.214583 ÷ MPG; the reverse conversion is MPG = 235.214583 ÷ L/100km. For example, 30 MPG is about 7.84 L/100km. These conversions describe fuel efficiency and are independent of fuel prices.

Tips to reduce fuel costs

Maintain steady highway speeds, keep tires properly inflated, and avoid rapid acceleration. Carpooling with one other person can halve each person's share of the fuel bill when costs are split equally. Use the passenger field above to see that share; the calculator does not model unequal contributions.

Electric vehicle comparison

The cost per mile for an EV is: (electricity rate in $/kWh) ÷ (miles per kWh). At an average US electricity rate of $0.16/kWh and an EV efficiency of 3.5 miles/kWh, driving costs approximately $0.046/mile. At $3.50/gal and 30 MPG, a gasoline vehicle costs approximately $0.117/mile - roughly 2.5× higher. At 15,000 miles/year, the difference is about $1,065 annually in energy savings. This comparison is illustrative: rates, driving conditions, and vehicle efficiency vary, and the calculator above estimates gasoline or diesel fuel only.

Gas price impact

A $0.50/gallon price increase on a vehicle getting 30 MPG driven 15,000 miles/year adds approximately $250 per year to fuel costs. The same price increase on a 20 MPG vehicle adds $375 per year. Improving fuel economy from 20 to 30 MPG at $3.50/gallon saves more than the same $0.50/gallon fuel price decrease at 20 MPG.

Frequently asked questions

How do I calculate fuel cost for a trip?

Divide the trip distance by your vehicle's fuel economy (MPG) to get gallons needed, then multiply by the price per gallon. For example, a 300-mile trip in a 30 MPG car at $3.50/gal costs (300 ÷ 30) × $3.50 = $35.

How do I convert MPG to L/100km?

Use L/100km = 235.214583 ÷ MPG; for the reverse conversion, use MPG = 235.214583 ÷ L/100km. Switching the calculator between Imperial and Metric converts the distance and fuel economy, but clears the pump-price field because local prices per gallon and per liter differ. Enter the current local price after switching.

What is a good MPG for a car?

For most passenger cars, 30–40 MPG on the highway is considered good fuel economy. Hybrid vehicles typically achieve 50–60 MPG, while fuel-efficient compact cars can exceed 40 MPG.

How do I split fuel costs between passengers?

Enter the number of people sharing the trip in the "Split between" field. When you enter more than one person, the calculator divides the total fuel cost equally and shows the per-person amount. At one person, that amount is already the total, so the separate per-person row is hidden.

How does the round-trip option work?

Enter the one-way distance and select Round trip. The calculator doubles that distance for fuel and cost estimates while keeping your entered one-way distance unchanged. Leave One way selected if your distance already includes the return journey.