Fuel Cost Calculator

Fuel Cost Calculator

Plan any drive with a free estimate for gas, diesel, or EV. See your total fuel use, cost per mile or kilometer, and each passenger’s share.

Your trip details

Enter three details below. Your estimate updates instantly.

Vehicle type
Units
2 Enter trip details
Enter the route distance yourself or paste it from your map app.
3 Add fuel efficiency and price
Use your car's combined MPG rating.
$
Enter the current price shown at the pump.
4 Add extras and split the cost
$
Added once to the full calculation.
Split the cost Divide the total between everyone in the car.
The total is split equally. Count the driver if they are paying a share.
Round trip Automatically doubles the entered distance.
Regular commute Project this trip by week, month, and year.
Use a round trip above if the distance is one way.
Reduce this for vacation and time off.
Useful for regular commutes or repeated journeys.
How far you drove on the fuel below — a full tank works best.
What it took to fill the tank back up.
Thinking about an EV? Compare what the same trip costs in a gas car vs. an electric car. Compare gas vs. electric

Calculate Trip Fuel Cost

Use the calculator for a one-way drive, round trip, road trip, or several identical journeys. Enter the distance, your vehicle's real fuel economy, and the current price at the pump or charger. The result includes fuel or electricity used, total driving cost, cost per mile or kilometer, and an equal cost per person when you are sharing the ride.

1. Add the distance Use miles or kilometers and switch on round trip when needed.
2. Add efficiency Choose the exact MPG, L/100 km, km/L, or EV unit your vehicle uses.
3. Add and split costs Include tolls, parking, and other costs before dividing the total.

Supported Fuel and Energy Units

  • Distance: miles and kilometers
  • Fuel economy: MPG (US), MPG (UK), miles/L, km/L, and L/100 km
  • EV efficiency: miles/kWh, km/kWh, kWh/100 mi, and kWh/100 km
  • Energy price: per US gallon, imperial gallon, liter, or kWh

Calculate Commute Cost

To estimate the cost of driving to work, enter the route as one round trip or enter the one-way distance and switch on Round trip. Under More options, turn on Regular commute, then enter how many days you drive each week and how many weeks you work each year. The result shows weekly, average monthly, and annual commute cost. Parking, bridge fees, and road tolls can be included before the projection, so the estimate reflects more than gas alone.

Split Fuel Cost Between Passengers

Switch on Split the cost and enter the total number of people in the car, including the driver if the driver is paying a share. The calculator adds fuel or charging cost and any extras, then divides the full amount equally. This makes it useful as a road trip gas split calculator, a carpool cost calculator, or a quick way to work out fair gas money for passengers. If your group also needs to divide hotels, meals, or activities, move the final driving total into the Trip Expense Splitter.

Calculate EV Charging Cost

Choose Electric, enter your EV's efficiency, and add the electricity price per kWh. You can use miles per kWh or kilometers per kWh when your dashboard shows distance per unit of energy. If it shows consumption, choose kWh/100 miles or kWh/100 km instead. An optional charging loss percentage is available under More options. Leave it at 0% when you want the battery-use estimate only, or add a measured loss when you want a closer estimate of energy drawn from the charger.

How the Fuel Cost Formula Works

The calculation first converts the selected distance and efficiency into fuel or electricity used. It keeps full precision through every step and rounds displayed money to two decimal places. Tolls, parking, and other expenses are added only after the energy cost is calculated.

Fuel used = distance ÷ fuel economy
Fuel cost = fuel used × price per gallon or liter
Total trip cost = fuel cost + tolls + parking + other costs
Cost per person = total trip cost ÷ total people sharing

For L/100 km, the tool uses liters = kilometers × L/100 km ÷ 100. For an EV rated in kWh/100 km, it uses kWh = kilometers × kWh/100 km ÷ 100. A round trip doubles distance before fuel use is calculated; the number-of-trips option then multiplies the complete journey.

US vs Imperial Gallons

A US gallon and a UK imperial gallon are not the same size. One US gallon equals 3.785411784 liters, while one imperial gallon equals 4.54609 liters. That difference also means a UK MPG figure cannot be entered as MPG (US) without changing the result. Choose MPG (US) for US vehicle data and fuel sold per US gallon. Choose MPG (UK) for an imperial MPG rating; the calculator then converts fuel use through imperial gallons and lets you pair it with price per imperial gallon or price per liter. The explicit labels are there to prevent one of the most common fuel-cost errors.

MPG, L/100 km, and km/L Explained

UnitWhat it meansHow to read it
MPG (US)Miles traveled per US gallonA higher number means better fuel economy.
MPG (UK)Miles traveled per imperial gallonUse only with an imperial MPG rating.
L/100 kmLiters used to travel 100 kilometersA lower number means better fuel economy.
km/LKilometers traveled per literA higher number means better fuel economy.
mi/kWhMiles traveled per kilowatt-hourA higher number means a more efficient EV.
kWh/100 kmElectricity used over 100 kilometersA lower number means a more efficient EV.

Fuel Cost Calculator Examples

Weekend road trip with friends

A 300-mile round trip at 30 MPG uses 10 US gallons. At $3.50 per gallon, fuel is $35. Add $15 in tolls and split between four people: $12.50 each.

Daily gasoline commute

A 24-mile round trip at 32 MPG uses 0.75 gallon per workday. At $3.60 per gallon, that is $13.50 per five-day week before parking or tolls.

European motorway trip

A car rated at 6.5 L/100 km uses 32.5 liters over 500 km. At €1.80 per liter, fuel costs €58.50 before motorway tolls.

EV charged at home

An EV using 18 kWh/100 km needs 36 kWh for 200 km. At €0.30 per kWh, charging costs €10.80 before an optional charging-loss adjustment.

Diesel van delivery

A 180-mile delivery at 24 MPG (US) uses 7.5 gallons. At $3.90 per gallon, estimated diesel cost is $29.25.

One way vs. round trip

If a 100-mile one-way drive costs $18, switching on round trip uses 200 miles and makes the equivalent estimate $36, assuming the same conditions.

Frequently Asked Questions

How do I calculate fuel cost for a trip?

Divide the trip distance by your vehicle's fuel economy to find fuel used, then multiply by the price per gallon or liter. Add tolls, parking, and other trip costs afterward.

How much gas will my trip cost?

Enter the route distance, MPG, and current gas price in the calculator. It returns gas needed, gas cost, and total trip cost immediately.

How do I calculate gas cost per mile?

Divide total gas and trip expenses by the total miles driven. The result panel calculates this automatically as cost per distance.

How do I split gas cost between passengers?

Add all shared driving expenses, switch on Split the cost, and enter the total people paying. The tool divides the full amount equally.

Does the driver count in the gas split?

Yes, if the driver is paying a share. Enter everyone who contributes, including the driver. Leave the driver out only when the group has agreed the driver pays nothing.

How do I calculate round-trip fuel cost?

Enter the one-way distance and switch on Round trip. The calculator doubles the distance before calculating fuel use and cost.

How do I calculate weekly, monthly, or annual commute cost?

Set up one commute day, turn on Regular commute, and enter commute days per week and working weeks per year. The result shows all three periods.

What is the difference between MPG (US) and MPG (UK)?

MPG (US) uses a 3.785-liter US gallon. MPG (UK) uses a 4.54609-liter imperial gallon, so the same numeric MPG value represents different fuel use.

How do I convert MPG to L/100 km?

For US MPG, divide 235.214583 by MPG. For example, 30 MPG (US) is about 7.84 L/100 km.

How do I calculate petrol or diesel trip cost in liters?

Choose kilometers and liters, enter km/L or L/100 km, then enter the petrol or diesel price per liter. The fuel type does not change the formula.

How do I calculate EV charging cost for a trip?

Calculate the kWh needed from distance and EV efficiency, then multiply by electricity price per kWh. Add charging loss only when you want to estimate energy drawn from the charger.

Can I add tolls and parking?

Yes. Put all additional shared driving expenses in the tolls, parking, and other costs field. They are added once per complete calculation.

Should I enter one-way or round-trip distance?

Enter the distance you already know. If it is one way and you will return, switch on Round trip. Do not switch it on when your entered distance already includes both directions.

Is the result exact?

No. It is an estimate based on your inputs. Traffic, speed, weather, elevation, cargo, tire pressure, charging losses, and driving style can change real consumption.

Related Tools

Trip Expense Splitter Track fuel, hotels, meals, and activities, then see who owes whom. Expense Splitter Split unequal shared costs across a group and settle the balances. Gas vs. Electric Calculator Compare the cost of driving the same distance in two vehicles. Split Bill Calculator Split a restaurant bill, tax, and tip quickly and fairly.

Method and review: Calculations use 1 mile = 1.609344 km, 1 US gallon = 3.785411784 L, and 1 imperial gallon = 4.54609 L. The page keeps full internal precision and rounds displayed money to two decimals. Methodology reviewed by the Split Bill Calculator editorial team. Last updated July 20, 2026. For a separate official US trip-cost reference, see FuelEconomy.gov.

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