Fuel Economy, Gas Cost and Trip Cost Calculator

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.
Results update automatically. Use “Copy URL” to keep the same inputs when sharing.

Switching unit systems changes labels only; it does not convert the numbers you already typed.

Inputs

Enter typical values for your route. Currency is cosmetic; the calculator works with any symbol.

What do you want to calculate?

Use this when planning a route and you know the distance, your car’s fuel economy and the gas price.

Unit system

You can switch anytime; results will be shown using this unit set.

Currency (optional)

Symbol only (for example $, €, ¥). Keep numbers plain in the other fields.

Distance driven and fuel used (actual)

Enter distance directly Use odometer readings

Distance driven (km)

Odometer at start

Use start and end only if you prefer automatic distance.

Odometer at end

Fuel used (L)

Gas price (per L)

Route and car information

One-way distance (km)

Round trip (there and back)

If unchecked, calculations use one-way distance only.

How is your car’s fuel economy given?

km/L L/100km mpg

Fuel economy value (km/L)

Gas price (per L)

Show monthly estimates (optional)

Turn this on if you want to see monthly distance, fuel use and gas cost for this route.

How many round trips per month? (optional)

Other trip costs

Add tolls, parking and other costs

Leave this off if you only want to split the gas cost. Turn it on to include extra costs.

Tolls

Parking

Car rental / car sharing

Other trip costs (optional)

Number of people sharing the cost

Leave any field blank to treat it as zero. Use whole numbers for people.

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.

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.