Fuel Cost Calculator
Calculate the fuel cost of a trip based on distance, fuel efficiency, and fuel price.
About the Fuel Cost Calculator
Estimating the fuel cost of a road trip or daily commute helps with budgeting and comparing vehicles or routes. This calculator works with either MPG or L/100km efficiency ratings and computes the total fuel needed and its cost for any trip distance.
How It Works
In MPG mode, the calculator divides trip distance by miles-per-gallon to find gallons needed. In L/100km mode, it multiplies distance by the L/100km rating and divides by 100 to find liters needed. Either way, it then multiplies the fuel needed by the price per unit to get total cost.
MPG mode: Fuel Needed = Distance / MPG. L/100km mode: Fuel Needed = Distance / 100 × L/100km. Cost = Fuel Needed × Price.
Worked example
Scenario: A 300-mile trip in a car that gets 28 mpg, with fuel at $3.50 a gallon.
- Fuel needed: 300 ÷ 28 = 10.71 gallons.
- Cost: 10.71 × $3.50 = $37.50.
Result: About $37.50 in fuel for the trip.
Tips and common mistakes
- For metric, choose L/100 km: 500 km at 7 L/100 km and 1.80 per liter uses 35 L and costs 63.
- Double the distance for a round trip.
- Highway and city driving differ; use the rating that matches the route.
Assumptions & Limitations
- Assumes consistent fuel efficiency across the entire trip, without adjusting for highway versus city driving mix.
- Fuel price is assumed constant for the full trip.
- Does not account for tolls, other trip expenses, or efficiency changes from cargo load, terrain, or driving style.
Estimating a trip realistically
Fuel cost depends on distance, fuel economy and fuel price. For a round trip, include both directions. Actual consumption can change with traffic, speed, idling, weather, tyre pressure, vehicle load and driving style.
Example: a 300 km trip at 8 L/100 km uses about 24 litres. At $1.50 per litre, the estimated fuel cost is $36.