How to use (3 steps)
- Pick what you need: real-world fuel economy, gas cost from distance, or full trip cost with split per person.
- Select Metric or US/Imperial units, enter distance and fuel economy (or odometer data), and add tolls or parking if needed.
- Press Calculate or edit an input to update results. Use “Copy URL” to keep the same inputs when sharing.
Switching unit systems converts the numbers you already typed so distance, fuel, fuel economy, and price stay consistent.
Inputs
Enter typical values for your route. Currency is cosmetic; the calculator works with any symbol.
Enter or adjust the values on the left to see fuel economy, gas cost, and per-person totals here.
What these results mean
Values will summarize your chosen mode: fuel economy in km/L, gas cost per trip, or cost per person.
Figures are rounded to 2 decimals. Real-world results vary with traffic, driving style, weather and load.
How it’s calculated
- Fuel economy (km/L) = distance (km) ÷ fuel used (L). Fuel consumption in L/100km is fuel per 100 km. mpg shows miles per gallon. All three are converted internally so you can compare them.
- Gas cost = fuel used × price per liter (or per gallon converted into price per liter).
- Round-trip calculations double the one-way distance; monthly estimates multiply by the number of round trips.
- Total trip cost = gas cost + tolls + parking + rental + other. Cost per person divides that total by the number of people.
- These are estimates only; actual fuel economy and prices change with road, weather, and vehicle conditions.
Worked examples & planning tips
Mini example (US units)
- Inputs: distance 500 miles, fuel economy 30 mpg, gas price $3.50/gal.
- Fuel used: 500 ÷ 30 = 16.666… gal.
- Gas cost: 16.666… × 3.50 ≈ $58.33.
- With extras: add $25 tolls + $15 parking → total ≈ $98.33.
- Split: 4 people → about $24.58 per person.
Tips to get a more realistic number
- Use real-world mpg: highway vs city, speed, cargo, cold weather, and idling can change fuel economy a lot.
- Round trip: double the distance if you are calculating there-and-back.
- Detours & stop-and-go: add a buffer in distance or use a lower mpg if you expect heavy traffic.
- Unit switch note: switching unit systems converts the numbers you already typed so distance, fuel, fuel economy, and price stay consistent.
References
FAQ
Which unit system should I pick?
Choose Metric (km, L) for km/L or L/100km inputs. Choose US/Imperial for miles and gallons. The calculator converts between them internally, so results stay comparable.
How are km/L, L/100km and mpg converted?
All fuel economy values are turned into liters per kilometer internally. km/L is inverted, L/100km is divided by 100, and mpg is converted from miles and gallons. The calculator then reports all three formats rounded to two decimals.
Do I have to enter tolls or parking?
They are optional. If you leave them blank or zero, totals will only include gas. Adding tolls, parking or rental fees gives a fuller picture for road trips.
Is my data saved or sent somewhere?
Everything runs in your browser. Values are not sent to a server. Use the “Copy URL” button only when you want to share a scenario deliberately.
What should I enter first for trip fuel cost?
Enter trip distance, vehicle efficiency, fuel price, and passenger or split assumptions first. Keep the unit system consistent before comparing route or vehicle options.