Fuel cost for 50 miles at 30 mpg
Here’s the fuel needed and cost for a 50-mile trip at 30 mpg and $3.5/gallon.
Different distance, mpg, or price? Use the full fuel cost calculator above.
About the fuel cost calculator
This calculator estimates how much fuel a trip will use and what it will cost, based on the distance you're driving, your vehicle's fuel efficiency, and the current price of fuel. It works in two common measurement systems: miles with miles-per-gallon (mpg) and dollars per gallon, or kilometers with liters-per-100km and price per liter — so it's useful whether you think in US customary units or metric.
In mpg mode, the math is straightforward: divide your trip distance in miles by your vehicle's mpg rating to get the gallons of fuel needed, then multiply that by the price per gallon to get the total cost. A 300-mile trip in a car that gets 30 mpg needs 10 gallons — at $3.50 a gallon, that's $35 in fuel.
In metric mode, fuel efficiency is usually expressed the opposite way — liters used per 100 kilometers traveled, rather than distance per unit of fuel. To find liters needed, divide your distance by 100, then multiply by your car's L/100km rating. Multiply that result by your price per liter to get the total cost. Lower L/100km numbers mean better efficiency, which is the reverse of mpg, where higher numbers are better.
Fuel efficiency isn't fixed — it varies with driving style, terrain, vehicle load, tire pressure, and whether you're mostly on the highway or in stop-and-go city traffic. The mpg or L/100km figure on a vehicle's window sticker or manual is typically a combined estimate, so your real-world results for a specific trip may run higher or lower, especially for mountainous routes, cold weather, or heavy traffic.
This tool is handy for budgeting a road trip, comparing the running costs of two different vehicles, or estimating how much a daily commute costs in gas over a month or year. For the most accurate results, use your own vehicle's actual observed fuel economy (miles driven divided by gallons used) rather than the official estimate, and update the price per gallon or liter to match current prices at the pump.
Fuel cost calculator questions
How trip fuel cost and efficiency are calculated.
How do I calculate fuel cost for a trip?
Divide your trip distance by your vehicle's fuel efficiency (mpg) to get gallons needed, then multiply by the price per gallon. For metric units, divide distance by 100, multiply by your car's L/100km rating, then multiply by the price per liter.
What's the difference between mpg and L/100km?
Mpg (miles per gallon) measures how far you travel per unit of fuel — higher is better. L/100km measures how much fuel is used over a fixed distance — lower is better. They measure efficiency in opposite directions, so they can't be compared directly without converting.
Where do I find my car's fuel efficiency?
Check your vehicle's window sticker, owner's manual, or manufacturer specifications for the official combined mpg or L/100km rating. For a more accurate real-world number, divide the miles or kilometers you actually drove by the fuel you used to refill the tank.
Why is my actual fuel cost different from the estimate?
Real-world fuel efficiency varies with driving style, terrain, vehicle load, weather, and traffic conditions. Highway driving is usually more efficient than city driving, and official ratings are combined averages that may not match your specific trip.
Does this calculator account for tolls or other trip costs?
No — this tool only estimates fuel cost based on distance, efficiency, and fuel price. Tolls, parking, maintenance, and other trip expenses need to be added separately.
How can I estimate my monthly commuting cost?
Calculate the fuel cost for a single round-trip commute, then multiply by the number of days you commute per month for a rough monthly estimate.
Does a higher mpg always mean lower fuel costs?
Generally yes for the same distance, but total cost also depends on fuel price and how much you drive. A more efficient car driven many more miles can still cost more in total fuel than a less efficient car driven rarely.