Use fuel cost to budget a specific trip.
Use this calculator when you know how far you expect to drive, your vehicle’s average fuel economy, and the expected price per litre or gallon. It estimates fuel consumed, total fuel spend, and fuel cost per mile or kilometre.
It is a trip-cost tool rather than only an efficiency converter. Select US MPG, imperial MPG, L/100 km, or km/L directly; use Fuel Economy when you only need to translate a rating.
Cost, efficiency, energy, and power answer different questions.
Fuel Cost combines distance, efficiency, liquid volume, and fuel price to estimate trip spending. Fuel Economy only converts efficiency units. EV Charging Cost prices electrical energy added to a battery, while EV Charging Time estimates ideal duration from energy and charger power.
Formula and calculation method.
Trip cost = converted fuel used × price per selected liquid unitThe selected distance and efficiency are normalized to one consistent fuel-use rate. The tool then expresses consumption in litres, US gallons, or imperial gallons and multiplies by the entered price for that unit.
See the transport decision, not just the math.
320 miles, 28 MPG, and $3.65 per gallon
Working: 320 ÷ 28 = 11.43 gallons; 11.43 × $3.65
Result: $41.71 fuel cost and about $0.13 per mile
Interpretation: This is a fuel-only estimate; tolls, parking, lodging, and vehicle wear are separate.
150 miles, 42 MPG, and $3.40 per gallon
Working: 150 ÷ 42 = 3.57 gallons; 3.57 × $3.40
Result: $12.14 fuel cost and about $0.08 per mile
Interpretation: Higher MPG lowers gallons and cost when distance and fuel price stay fixed.
Put the estimate in context.
Treat the result as a planning estimate. Actual MPG can fall with congestion, cold starts, roof loads, towing, steep grades, high speed, or aggressive acceleration.
For a round trip, enter the complete round-trip distance. For comparing vehicles, keep distance and fuel price fixed and change only the efficiency rating.
Assumptions and common mistakes.
What the calculation assumes
- Distance, efficiency, liquid volume, and price use the units and denomination selected above the inputs.
- Average fuel economy and fuel price remain constant for the full trip.
- The trip starts and ends without adding detours, idling, or separate fuel-consuming use.
- The estimate covers fuel only, not other vehicle or travel costs.
Mistakes to avoid
- Selecting US MPG when the source rating uses an imperial gallon, or selecting MPG when the source is L/100 km.
- Entering one-way distance when budgeting a round trip.
- Using a best-case highway rating for mixed or city driving.
- Entering total fill-up price instead of price for one selected litre or gallon.
What unusual inputs mean.
No trip fuel is modeled, so gallons and fuel cost are zero.
Fuel use would require division by zero, so the calculator returns an error.
Gallons are still estimated, but the calculated monetary cost is zero.
What this tool leaves out.
This calculator does not predict live pump prices, currency exchange rates, route elevation, traffic, weather, idling, towing, seasonal fuel blends, or vehicle-specific efficiency. It does not include tolls, maintenance, depreciation, or plug-in charging.
Automotive and energy questions.
How do I calculate fuel cost for a trip?
Convert distance and efficiency to a consistent basis, calculate fuel used, then multiply by the price per selected litre or gallon.
Should I enter one-way or round-trip distance?
Enter the total distance you want to budget. Add both directions when planning a round trip.
Can I use L/100 km in this calculator?
Yes. Select L/100 km for efficiency and kilometres for distance; the tool also supports US MPG, imperial MPG, and km/L.
Why can actual fuel cost be different?
Actual MPG and pump prices vary with traffic, speed, weather, terrain, vehicle load, driving style, and where you refuel.
Does this include tolls or vehicle wear?
No. The result covers estimated fuel only.