AUTO CALCULATOR
Fuel Cost Calculator
Estimate trip fuel cost from distance, vehicle efficiency, pump price, round-trip travel and recurring driving. Compare fuel prices, MPG, route length and annual fuel spending in one place.
Fuel trip details
Build a fuel estimate from your route, efficiency and pump price.
Trip
Vehicle efficiency
Fuel price
Recurring travel
Use 52 for a full-year estimate.
Fuel estimates vary with speed, traffic, weather, load, tires and driving style.
Your trip fuel estimate will appear here
Enter your distance, fuel economy and pump price, then select Calculate Fuel Cost.
How Much Will a Trip Cost in Fuel?
A trip's fuel expense depends mainly on distance, fuel economy and the price you pay at the pump. This calculator combines those inputs to estimate fuel required, trip cost, cost per mile or kilometer, and a simple annual fuel budget.
If you want to calculate your real-world efficiency first, use the measured fuel economy. If your vehicle uses another measurement system, the unit conversion tool can help convert MPG, L/100 km and km/L.
Fuel Cost Formula
For MPG, the basic calculation is:
Fuel cost = fuel used × fuel price
For example, 300 miles at 25 MPG requires about 12 gallons. At $3.50 per gallon, the estimated fuel cost is $42.
How far you drive.
How much distance your vehicle gets from fuel.
What each gallon or liter costs.
How often the same trip occurs.
Fuel Cost Calculation Reference
| Measurement | Formula | Purpose |
|---|---|---|
| Fuel used in MPG | Distance ÷ MPG | Gallons required |
| Fuel used in L/100 km | km × L/100 km ÷ 100 | Liters required |
| Fuel cost | Fuel used × price | Trip expense |
| Cost per mile | Trip cost ÷ miles | Fuel running cost |
| Cost per kilometer | Trip cost ÷ kilometers | Metric running cost |
| Annual fuel cost | Trip cost × recurring trips | Simple yearly fuel budget |
MPG vs. L/100 km vs. km/L
MPG measures distance traveled per gallon, so higher MPG generally means better efficiency. L/100 km measures liters needed for 100 km, so lower L/100 km generally means better efficiency. km/L behaves like MPG: higher is generally better.
When comparing vehicles, make sure their efficiency figures use the same basis. The convert fuel economy units is useful when the figures come from different measurement systems.
Fuel Cost Example
A round trip would double the route to 600 miles and, under the same assumptions, double the estimated fuel expense to about $84.
How Fuel Price Changes Trip Cost
Fuel price has a direct relationship with fuel expense. If a trip uses 10 gallons, every $0.50 change in the price changes the trip estimate by about $5. Testing several prices is useful when planning a long journey because pump prices may vary between locations or dates.
How Fuel Economy Changes Cost
Two vehicles can travel the same route while consuming different amounts of fuel. A 30 MPG vehicle uses less gasoline than a 20 MPG vehicle for the same distance. Over repeated commuting, the difference can become much more noticeable.
For your own vehicle, observed fuel economy can be more useful than a brochure figure. Use the actual driving results to calculate efficiency from actual distance and fuel used.
Round Trips and Recurring Travel
A common estimating mistake is entering a one-way distance when the real plan is to return home. Enable round trip when appropriate. For commuting or repeated journeys, enter trips per week and weeks per year to turn a single-trip estimate into an annual fuel budget.
Fuel Cost per Mile and Kilometer
Cost per mile and cost per kilometer normalize fuel expense so you can compare routes or vehicles. They describe fuel only, not the complete cost of operating a car.
For the financing side of ownership, use the monthly auto financing. To estimate the maximum payment or vehicle price that fits your budget, use the vehicle budget estimate. Depreciation can be explored with the vehicle value loss.
What Can Make Actual Fuel Use Different?
Real-world consumption can vary because of traffic, speed, acceleration, hills, weather, tire pressure, cargo, air conditioning, road surface, maintenance and driving style. Treat the calculator as a planning estimate rather than a guarantee of actual pump spending.
- Stop-and-go traffic can reduce efficiency.
- High speeds can increase fuel consumption.
- Heavy cargo and roof equipment can add resistance or weight.
- Weather and climate control can change fuel use.
- Tire pressure and vehicle condition can affect efficiency.
How to Get a Better Estimate
- Use recent real-world fuel economy when available.
- Use the pump price you expect to encounter.
- Include the full round-trip distance when appropriate.
- Test a higher price to create a planning cushion.
- Use your actual recurring driving schedule for annual planning.
Fuel Cost vs. Total Cost of Driving
Fuel is only one part of vehicle ownership. Insurance, maintenance, repairs, tires, registration, parking, tolls, financing and depreciation can also affect the true cost of transportation. A low fuel bill does not necessarily mean a low total cost of ownership.
If you are evaluating a vehicle purchase, start with the affordable vehicle price for the financing side, then add fuel and other ownership expenses.
Fuel Cost Comparison
| Example | Efficiency | Fuel for 300 mi | Cost at $3.50/gal |
|---|---|---|---|
| Less efficient | 15 MPG | 20.00 gal | $70.00 |
| Average example | 25 MPG | 12.00 gal | $42.00 |
| More efficient | 30 MPG | 10.00 gal | $35.00 |
| Highly efficient | 35 MPG | 8.57 gal | $30.00 |
Fuel Cost Calculator FAQs
How do I calculate fuel cost for a trip?
Divide distance by fuel economy to estimate fuel used, then multiply by the fuel price. For L/100 km, calculate liters as kilometers × L/100 km ÷ 100.
Does the calculator support MPG and L/100 km?
Yes. You can enter MPG, L/100 km or km/L and the calculator reports gallons and liters.
Should I use city or highway MPG?
Use the figure that best represents your planned driving. A recent real-world average is useful for mixed driving.
How do I calculate a round-trip fuel cost?
Enter the one-way distance and enable the round-trip option. The calculator doubles the distance before estimating fuel use.
Why can actual fuel cost differ?
Traffic, speed, weather, terrain, vehicle load, tire pressure, driving style and changing pump prices can all affect the result.
Can I estimate annual fuel costs?
Yes. Enter similar trips per week and weeks per year. The calculator multiplies the trip estimate by that recurring schedule.
Is higher MPG better?
Generally yes. Higher MPG means the vehicle travels farther on a gallon. For L/100 km, lower is generally better.
Does fuel cost include maintenance or insurance?
No. The estimate covers fuel only and excludes maintenance, insurance, depreciation, tolls, parking and other ownership expenses.
Can I compare two vehicles?
Yes. Run the calculator for each vehicle using the same route and fuel-price assumptions, then compare fuel use and cost per distance.