Gas Trip Cost Calculator
Enter the distance, your car’s fuel economy and the gas price to get the fuel cost of a trip. See one-way or round-trip costs, a monthly commute estimate and each rider’s share. Nothing is sent to a server.
Enter the distance, fuel economy and gas price and the cost is calculated automatically.
How to use
How this gas trip cost calculator works
This gas trip cost calculator tells you what a drive will cost in fuel. Enter the distance in miles, your vehicle’s fuel economy in miles per gallon (MPG) and the price you pay per gallon. The result updates as you type: the cost of the trip, the gallons of fuel needed and the cost per person if you are sharing the ride. Choose One way or Round trip (the distance is doubled), and add the number of commute days per month to see a monthly fuel budget. Pick Regular, Premium or Diesel so the price label matches the pump you use. Your entries are stored only in your own browser so they are there when you come back.
The formula
fuel cost = distance ÷ miles per gallon × price per gallon
Say your commute is 30 miles each way, your car gets 25 MPG and gas costs $3.60 a gallon. One way you burn 30 ÷ 25 = 1.2 gallons, which costs 1.2 × $3.60 = $4.32. Switch to Round trip and the distance becomes 60 miles, so you use 2.4 gallons and spend $8.64 a day. Over 20 commute days that is about $172.80 a month. If two coworkers carpool and split the fuel, each pays $4.32 a day on a round trip, or about $86.40 a month. The tool follows exactly this arithmetic, so you can check any result by hand.
A road trip example
Imagine a 480-mile drive each way in a car that gets 30 MPG, with gas at $3.50 a gallon. One way takes 480 ÷ 30 = 16 gallons, or $56. The round trip is $112. With four people in the car, each person’s share is $28. Fuel is only part of a trip, so you may also want to split tolls, parking and snacks; the Bill Split Calculator can divide those shared costs fairly.
Finding your MPG
The easiest source is the window sticker or the U.S. government’s fuel economy website, fueleconomy.gov, which lists EPA ratings for city, highway and combined driving. For a real-world number, fill the tank, reset the trip meter, drive normally and fill up again. Divide the miles driven by the gallons you added. Use the city rating for stop-and-go commutes and the highway rating for long trips. If your car shows an MPG average on its dashboard, that is a convenient starting point too.
Why your real cost can differ
- Speed. Gas mileage generally drops at higher highway speeds because of air resistance.
- Weather and terrain. Cold temperatures, strong headwinds and hilly roads all reduce MPG.
- Load and equipment. Heavy cargo, roof racks and towing use more fuel.
- Tire pressure and maintenance. Underinflated tires and neglected maintenance lower efficiency.
- Prices vary. Gas prices differ by state, city and even from one corner to the next. Use the price shown at your station or in a gas-price app, not a national average, for the best estimate.
Beyond fuel: the full cost of driving
Fuel is one of several costs of owning a car. Insurance, maintenance, tires, depreciation, registration and parking add up and are often larger than the gas bill. The IRS publishes a standard mileage rate each year for business, medical and charitable driving that is meant to include these costs, so it is higher than fuel alone. Check IRS.gov for the current rate if you are tracking deductible miles or reimbursing someone for a drive.
Ways to lower your fuel bill
- Carpool for commutes and split the cost with the Bill Split Calculator.
- Keep your tires inflated to the pressure on the driver’s door sticker.
- Smooth acceleration and braking save fuel compared with sudden starts and stops.
- Combine errands into one trip, since a warm engine is more efficient than several cold starts.
- Compare prices before long drives, and remember that premium fuel only helps if your engine requires it.
Comparing two cars or two routes
The calculator is also a quick way to compare options. Run the same 12,000-mile year through a 25 MPG car and a 40 MPG car at $3.50 a gallon: the first burns 480 gallons and costs $1,680, while the second burns 300 gallons and costs $1,050, a difference of $630 a year. A longer but faster highway route can beat a shorter stop-and-go route because MPG is higher at steady speeds, so enter a different MPG for each route if you know it. Remember that tolls and travel time have a price too.
Planning a long trip
For a long drive, add a cushion of 10% to 15% to your fuel estimate to cover detours, traffic and heavier loading. Gas prices can change a lot from state to state, so if your route crosses several states, use an average of the prices you expect to pay along the way. If you are renting a car, ask about the fuel policy: returning it with a full tank is usually cheaper than paying the rental company’s refueling charge.
Frequently asked questions
How do I calculate the gas cost of a trip?
Divide the distance in miles by your car’s miles per gallon to get the gallons needed, then multiply by the price per gallon. For 100 miles at 25 MPG and $3.50 a gallon, you need 4 gallons and spend $14.
What MPG should I use?
Use the combined rating on your car’s sticker or on fueleconomy.gov, or your own measured average. For a long highway drive the highway number is more accurate, and for commuting in traffic the city number is closer to reality.
Does the calculator convert kilometers or liters?
The tool is set for miles, MPG and dollars per gallon. To convert, one mile is about 1.609 kilometers and one US gallon is about 3.785 liters. To turn MPG into liters per 100 km, divide 235.2 by the MPG, so 28 MPG is about 8.4 L/100 km. The Unit Converter can help with other conversions.
How does the commute days field work?
It multiplies the cost of one trip by the number of days. If you want a daily round trip, set the trip to Round trip first so each day counts both directions.
Can I split the cost between passengers?
Yes. Enter the number of riders and the tool shows each person’s share of the trip and, if you entered commute days, the monthly share. A small chart shows how the total compares with one person’s part.
Does it work for electric vehicles?
Not directly. The formula needs gallons. For an EV, multiply the miles by your car’s kilowatt-hours per mile and your electricity price per kilowatt-hour to estimate the cost of a trip.
Is my data stored or shared?
Your inputs are saved only in your own browser so the form is filled when you return. Nothing is sent to a server. Use the Clear inputs button to remove them.
Related tools
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To compare fuel costs more precisely
After you work out the gas cost from distance and fuel economy, you can continue with these tools if several people split the cost or you need to convert units.