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Fuel Cost Calculator

Work out the gas or fuel cost of a trip: how much fuel you need, what it costs, the cost per mile and each person's share.

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  • No sign-up
  • Numbers stay in your browser

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Fuel cost calculation details

miles

How far you will drive.

MPG

Miles per gallon. Find it on your car's sticker or manual.

per gallon

The price of one US gallon.

Optional. Leave it as 1 if you drive alone.

The boxes start with example numbers. Change them to your own, then press Calculate.

Fuel cost calculation result

Total fuel cost
35
For 300 miles at 3.50 per gallon

Each of the 2 people pays 17.50. You need 10 gallons of fuel for the trip.

  • Fuel needed10 gal300 miles ÷ 30 MPG
  • Cost per mile0.1235 ÷ 300 miles
  • Each person pays17.502 people sharing

Fuel cost for common trip distances

DistanceFuel neededFuel costEach of 2
50 miles1.67 gal5.832.92
100 miles3.33 gal11.675.83
200 miles6.67 gal23.3311.67
300 miles10 gal3517.50
500 miles16.67 gal58.3329.17
1,000 miles33.33 gal116.6758.33

At 30 MPG and 3.50 per gallon. Your trip is highlighted.

Your fuel economy in other units

30 MPG (US)miles per US gallon
36.03 MPG (UK)miles per UK gallon
12.75 km/Lkilometers per liter
7.84 L/100 kmliters per 100 kilometers

The same fuel economy written four ways. Use it to compare cars from different countries.

Fuel cost formula

Fuel needed = Distance ÷ Fuel economy
Total fuel cost = Fuel needed × Gas price
Cost per mile = Total fuel cost ÷ Distance

In this example: 300 miles ÷ 30 MPG = 10 gal, then 10 gal × 3.50 = 35, and 35 ÷ 300 = 0.12 a mile.

Typical fuel economy

27.2 MPG
The average new US vehicle in model year 2024, a record high (real-world estimate)
25.5 MPG
The same average without electric and plug-in hybrid vehicles, which are 1.7 MPG lower
25.7 MPG
The average new truck SUV in model year 2024

Source: US Environmental Protection Agency, Automotive Trends Report. Your own car may be higher or lower, so use the number from your car.

300 miles at different MPG and prices

Fuel economy3 per gallon3.50 per gallon4 per gallon
20 MPG4552.5060
25 MPG364248
30 MPG303540
40 MPG22.5026.2530

What a 300 miles trip costs for one car. A better fuel economy or a cheaper price both lower the cost.

Popular use cases

Daily commuteEstimate your weekly gas cost
Road tripsPlan the fuel budget for a long drive
Sharing a rideSplit the cost between friends
Monthly budgetSee what fuel costs you every month

Easy ways to work out fuel cost

  • Cost per mile: gas price ÷ MPG. 3.50 ÷ 30 → 0.12
  • Gallons for a trip: miles ÷ MPG. 300 ÷ 30 → 10 gallons
  • Round trip: double the distance. 600 miles → 70
  • Split: divide the total by the number of people.

What is included

  • Fuel needed for the trip
  • The total gas, petrol or fuel cost
  • Cost per mile or per kilometer
  • Each person's share
  • Round trip, counted both ways
  • MPG (US and UK), km/L and L/100 km

Important to know

Real fuel use depends on speed, traffic, load, weather and how you drive, so use it as an estimate. Tolls, parking and car costs are not included. It works for petrol and diesel, not for electric cars.

Use this free fuel cost calculator, also called a gas cost or trip cost calculator, to work out what a trip will cost in gas, petrol or diesel. Pick the unit your car uses (MPG, km/L or L/100 km), then enter the trip distance, the fuel economy and the fuel price. You see the fuel you will need, the total cost, the cost per mile or kilometer and, if you are sharing the trip, each person's share. Tick round trip to count the way back. Tables show the cost of common distances and your fuel economy in other units. It is free and instant, and your numbers stay in your browser.

How to calculate the fuel cost of a trip

The cost of a trip depends on three things: how far you go, how much fuel your car uses for that distance, and what the fuel costs. First work out the fuel you will need, then multiply it by the price.

MPG: fuel = distance (miles) ÷ MPG
km/L: fuel = distance ÷ km/L
L/100 km: fuel = distance × L/100 km ÷ 100
Cost: cost = fuel × price per gallon (or per liter)
Cost per mile: cost ÷ distance

Example: a 300 mile trip in a car that does 30 MPG, with gas at $3.50 a gallon. The car needs 300 ÷ 30 = 10 gallons, so the gas costs 10 × $3.50 = $35. That is about $0.12 for every mile.

Round trips and sharing the cost

Tick Round trip and the distance you enter is counted twice. The same journey there and back is 600 miles, which needs 20 gallons and costs $70. The cost for each mile stays the same.

Enter the number of people to split the total. Shared between 2 people, the $70 round trip is $35 each, and the one-way trip above is $17.50 each.

Fuel economy units explained

Different countries measure fuel economy in different ways. MPG (miles per gallon) and km/L go up when a car is more efficient. L/100 km goes down when a car is more efficient, because it measures how much fuel is used, not how far you get. A US gallon (3.785 liters) is smaller than a UK gallon (4.546 liters), so the same car has a higher MPG figure in UK gallons.

km/LL/100 kmMPG (US)MPG (UK)
812.5018.8222.60
1010.0023.5228.25
12.58.0029.4035.31
156.6735.2842.37
205.0047.0456.50

Average fuel economy in the US

The US Environmental Protection Agency estimates that the average new US vehicle in model year 2024 does 27.2 MPG in real-world driving, a record high. Without electric and plug-in hybrid vehicles the average is 25.5 MPG, and the average new truck SUV is 25.7 MPG. Your own car may be higher or lower, so use the number for your car when you can.

How to find your car's real fuel economy

The figure on the window sticker or in the brochure is measured in test conditions, so real driving is usually a little different. To find yours:

  • Fill the tank completely and note the trip meter (or reset it to zero).
  • Drive as you normally do until the tank is about half empty or lower.
  • Fill the tank completely again and note how many gallons (or liters) it took.
  • Divide the distance driven by the fuel added to get MPG (or km/L). Do the sum a few times for a steadier figure.

Ways to spend less on fuel

  • Drive smoothly. Hard acceleration and braking use more fuel.
  • Keep your tyres at the recommended pressure.
  • Remove roof racks and heavy things you do not need to carry.
  • Avoid leaving the engine idling, and combine short errands into one trip.
  • Share the journey. Splitting the cost, as this calculator can do, makes long trips much cheaper per person.

This calculator is for petrol, diesel and gas vehicles. Electric cars are charged in kilowatt hours rather than gallons or liters, so the figures do not apply to them.

Sources

The rules, rates and ranges on this page come from these sources. Always check the current figures with the organization itself before you rely on them.

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Frequently Asked Questions

How do I calculate the gas cost of a trip?

Divide the distance by your car's MPG to get the gallons you need, then multiply by the gas price. For 300 miles at 30 MPG you need 10 gallons, and at $3.50 a gallon that costs $35.

How do I calculate the cost per mile?

Divide the gas price by your MPG. $3.50 ÷ 30 MPG is about $0.12 a mile. You can also divide the total cost by the distance: $35 ÷ 300 miles.

How do I split the fuel cost between passengers?

Enter the number of people sharing the cost. The result then shows each person's share of the total. In the example, $35 shared between 2 people is $17.50 each, and if you tick round trip the total doubles to $70, which is $35 each.

What is MPG and how do I calculate it?

MPG means miles per gallon: how many miles your car drives on one gallon of fuel. Fill the tank, drive, fill it again, and divide the miles driven by the gallons you added. 300 miles on 10 gallons is 30 MPG. You can also find it on the car's window sticker or in the manual.

What is the difference between US and UK MPG?

They use different gallons. A US gallon is 3.785 liters and a UK (imperial) gallon is 4.546 liters, so the same car has a higher MPG in UK gallons. 30 MPG (US) is about 36 MPG (UK). Choose the tab that matches how your fuel is sold.

How do I convert MPG to L/100 km or km/L?

Divide 235.215 by the US MPG to get L/100 km, so 30 MPG is about 7.84 L/100 km. Multiply US MPG by 0.425 to get km/L, so 30 MPG is about 12.75 km/L. After you calculate, the page also shows your fuel economy in all four units.

Does the round trip option include the way back?

Yes. Tick "Round trip" and the distance you entered is counted twice, so the fuel needed and the total cost double. The cost per mile or kilometer stays the same.

What is a typical fuel economy?

The US Environmental Protection Agency estimates that the average new US vehicle in model year 2024 does 27.2 MPG, a record high. Without electric and plug-in hybrid vehicles it is 25.5 MPG, and the average new truck SUV does 25.7 MPG. Your own car may be higher or lower.

Does it work for petrol and diesel?

Yes. It works for any fuel that is sold by the gallon or the liter, such as gasoline (petrol) and diesel. Enter the price of the fuel you use.

Does this work for electric cars?

No. It is designed for petrol, diesel and gas vehicles that are filled by the gallon or liter. Electric cars are charged in kilowatt hours, so the figures do not apply.

Does it include tolls, parking or other costs?

No. It works out the fuel cost only. Add tolls, parking and any other costs of the trip yourself.

Can I save, share or print my results?

Yes. After you press Calculate, use Copy link to get a link that opens the calculator with the same numbers, or Print for a clean printout. The numbers sit after the # in the link, a part of the address that browsers do not send to our server.

Are my numbers saved or shared?

No. The calculation happens in your browser, and the numbers you type are not stored or sent to any server.