Unit Converter
Convert length, mass, volume, area, speed and time units.
Free calculator
Fuel Cost Calculator
Estimate trip fuel use, total cost, cost per mile or kilometer, and per-person splits across explicit metric, US and Imperial units.
The calculation stays in your browser. Currency changes formatting only; units remain independently selectable and no exchange-rate conversion occurs.
How to use this tool
Normalize your entered distance, fuel-efficiency convention and fuel-price volume to kilometers, liters per 100 kilometers and price per liter, then estimate fuel use and cost.
Transparent method
Formula and method
Fuel cost = fuel used × normalized price per liter. L/100 km uses liters = distance km × efficiency ÷ 100; MPG uses distance miles ÷ MPG with the selected gallon definition.
Worked examples
- US example: 300 miles ÷ 30 MPG (US) = 10 US gallons. At $3.50 per US gallon, fuel cost is $35, or about $0.12 per mile.
- Metric example: 500 km × 7.5 L/100 km ÷ 100 = 37.5 liters. At C$1.70 per liter, fuel cost is C$63.75.
- Imperial example: 300 miles ÷ 30 MPG (Imperial) = 10 Imperial gallons, or 45.4609 liters. At £1.55 per liter, fuel cost is about £70.46.
- Split example: the C$63.75 metric trip split between three people is C$21.25 per person.
- Round-trip example: 150 one-way miles at 30 MPG (US) and $3.50 per US gallon becomes 300 total miles and costs $35.
Assumptions and limits
- One mile equals exactly 1.609344 kilometers for this calculation.
- One US gallon equals 3.785411784 liters; one Imperial gallon equals 4.54609 liters. The two MPG conventions are not interchangeable.
- Distance, fuel-efficiency unit, fuel-price volume unit and currency are selected independently.
- USD, GBP and CAD affect display formatting only. No exchange-rate conversion occurs.
- A round trip doubles the entered one-way distance while leaving the displayed input unchanged.
- Results estimate fuel only. Tolls, parking, accommodation, vehicle wear and other trip costs are excluded.
- Actual consumption can vary with route, traffic, weather, load, driving style and vehicle condition.
How fuel cost is calculated
The calculator converts distance to kilometers, efficiency to liters per 100 kilometers and fuel price to a price per liter. Fuel used is then multiplied by the normalized price. This single internal model keeps mixed combinations—such as miles, L/100 km and price per Imperial gallon—consistent.
Full numeric precision is retained through distance, efficiency, volume and price conversion. Values are rounded only when displayed.
Trip distance and round trips
Enter the one-way or total trip distance and choose miles or kilometers explicitly. When Round trip is enabled, the calculator doubles the entered distance for fuel and cost without changing the original value shown in the form.
A zero-distance trip is valid and produces zero fuel and cost. Cost per mile and kilometer are reported as unavailable because dividing by zero distance has no meaningful result.
Fuel efficiency and fuel price
Efficiency must identify its convention: MPG (US), MPG (Imperial), L/100 km or km/L. Fuel price separately identifies price per liter, US gallon or Imperial gallon. Currency never chooses the units for you.
Fuel cost = fuel used × fuel price after both fuel quantity and price have been normalized to liters. A price of zero is valid; the estimated cost is then zero even though fuel used remains visible.
US MPG versus Imperial MPG
MPG (US) uses a 3.785411784-liter US gallon. MPG (Imperial) uses a 4.54609-liter Imperial gallon. Therefore, 30 MPG (US) and 30 MPG (Imperial) do not represent the same fuel consumption.
For 300 miles, 30 MPG (US) uses 37.85411784 liters, while 30 MPG (Imperial) uses 45.4609 liters. Always choose the convention used by the vehicle's efficiency figure.
Using liters per 100 kilometers
For L/100 km, liters used = distance in kilometers × L/100 km ÷ 100. Lower L/100 km values mean better fuel efficiency because less fuel is used to travel the same distance.
A 500-kilometer trip at 7.5 L/100 km uses 37.5 liters. At C$1.70 per liter, the fuel-only cost is C$63.75.
Using kilometers per liter
For km/L, liters used = distance in kilometers ÷ kilometers per liter. Higher km/L values mean better efficiency, which is the opposite direction from L/100 km.
The conversion to L/100 km is 100 ÷ km/L. For example, 12.5 km/L equals 8 L/100 km.
Cost per mile and cost per kilometer
Cost per mile equals total fuel cost divided by total trip miles. Cost per kilometer uses total kilometers. Both are shown regardless of the entered distance unit so trips and vehicle assumptions can be compared consistently.
Gallon-to-liter assumptions
The engine uses 3.785411784 liters per US gallon and 4.54609 liters per Imperial gallon without rounding those constants before calculation. Distance conversion uses exactly 1.609344 kilometers per mile.
US MPG converts to approximately 235.214583 ÷ MPG in L/100 km. Imperial MPG converts to approximately 282.480936 ÷ MPG. The calculator derives these relationships from the documented gallon and mile constants.
Splitting fuel cost
Enter a whole number of people to divide total fuel cost equally. A C$63.75 fuel cost split between three people is C$21.25 each. The split covers fuel only and does not add tolls, parking, accommodation or other expenses.
US, UK and Canadian terminology
US vehicle figures often use miles per US gallon, UK figures may use miles per Imperial gallon, and Canadian figures commonly use liters per 100 kilometers. These are general conventions, not automatic rules: use the explicit controls to match the source of your figures.
Common fuel-cost calculation mistakes
Common errors include mixing US and Imperial gallons, entering a per-gallon price as a per-liter price, pairing miles with a formula that expects kilometers, or forgetting to double a one-way distance for a return journey. Keeping each unit explicit prevents these mismatches.
What this calculator does not include
CorelyUp does not fetch live fuel prices, locate stations, use geolocation, calculate routes, look up a vehicle or estimate electric-vehicle charging. The user supplies distance, efficiency and fuel price. Results exclude tolls, parking, accommodation, vehicle wear and other travel costs.
Frequently asked questions
How do I calculate fuel cost for a trip?
Calculate fuel used from distance and efficiency, normalize the fuel price to the same volume unit, then multiply fuel used by fuel price. CorelyUp handles those unit conversions explicitly.
How do I calculate fuel used from MPG?
Divide miles traveled by MPG to get gallons used, then use the correct gallon definition: 3.785411784 liters for a US gallon or 4.54609 liters for an Imperial gallon.
What is the difference between US MPG and UK MPG?
US MPG uses US gallons and UK or Imperial MPG uses larger Imperial gallons. The same numeric MPG therefore represents different fuel consumption.
How do I calculate fuel cost using L/100 km?
Multiply distance in kilometers by L/100 km and divide by 100 to get liters, then multiply by the entered price per liter after any price-unit conversion.
What does km/L mean?
Kilometers per liter is the distance traveled on one liter. Higher km/L means better efficiency. Divide 100 by km/L to convert it to L/100 km.
How many liters are in a US gallon?
The calculator uses exactly 3.785411784 liters per US gallon.
How many liters are in an Imperial gallon?
The calculator uses exactly 4.54609 liters per Imperial gallon.
How do I calculate cost per mile?
Divide total fuel cost by total trip miles. For zero distance the calculator reports this value as unavailable instead of dividing by zero.
Can I split fuel cost between passengers?
Yes. Enter a whole number of people and the calculator divides the fuel-only cost equally between them.
Does this calculator include tolls or parking?
No. It estimates fuel only and excludes tolls, parking, accommodation, vehicle wear and other trip costs.