Fuel Cost Calculator

The Fuel Cost Calculator takes three numbers, trip distance, fuel consumption per 100 km and fuel price, and estimates how many litres the trip will use, what it will cost in total, and the average cost per kilometre. It is plain arithmetic. It does not look up today's fuel prices, adjust for traffic, load or air conditioning, or distinguish between petrol, diesel and electric cars. It works only with the numbers you type, so the result is only as good as the consumption figure you enter.

How to use it

1. Enter the one-way distance in "Distance (km)". The default is 100.
2. Enter your car's consumption in "Fuel consumption (L/100km)", the number of litres used per 100 km. The default is 7.5 and the field steps in 0.1.
3. Enter the price per litre in "Fuel price (CNY/liter)". The default is 7.8 and it steps in 0.01.
4. If you are driving both ways, tick "Round trip (distance is doubled)". The tool multiplies the distance by 2 so you do not have to change the number yourself.
5. Read the three results: fuel needed in litres, estimated cost, and cost per km. They update as you type.

Worked example

These figures come from running the tool's own formulas. With the defaults, 100 km at 7.5 L/100km and a price of 7.8 per litre, you need 7.50 L, spend 58.50 and pay 0.58 per km. Tick round trip and the distance becomes 200 km, so you need 15.00 L and spend 117.00, while the cost per km stays at 0.58. A longer trip: 350 km at 6.2 L/100km and 8.1 per litre needs 21.70 L, costs 175.77 and works out at 0.50 per km. The formulas are simple: litres = distance / 100 x consumption, and cost = litres x price.

Supported features and known limits

• It uses a single consumption figure and a single price. It cannot split a trip into city and motorway sections; if you need that, calculate each part separately and add the results.
• Tolls, parking, maintenance and depreciation are not included.
• An empty or unreadable field is treated as 0. When the distance is 0, the per-km figure shows 0.00.
• The inputs carry min=0, but the code does not block negative numbers, and a negative value produces a meaningless result.
• Units are fixed to kilometres, litres and CNY. If your consumption is in miles per gallon, convert it to litres per 100 km before entering it.
• For an electric car you could roughly plug in kWh per 100 km and a price per kWh, but the page labels say litres, so read "L" as kWh. That is only borrowing the formula, not a dedicated EV feature.
• Results are rounded to two decimal places.

What consumption figure should I enter?

The most reliable number is your own. Fill the tank, note the odometer, and at the next fill-up divide the litres added by the distance driven and multiply by 100. Many cars also show an average consumption on the dashboard. A manufacturer's quoted figure is usually measured under standard test conditions, and real use in heavy traffic, cold weather with the heater on, or with a full load is often higher.

Does the round-trip option double the consumption too?

No. It only doubles the distance. Consumption and price stay the same, so total litres and total cost double while the cost per kilometre does not change.

Do I have to look up the fuel price myself?

Yes. The tool does not fetch live prices. Enter what you actually pay per litre at the pump, for the grade of fuel you normally use.

Why does my real fill-up differ from the result?

The result depends entirely on the three numbers you typed, while real consumption changes with road conditions, speed, load and climate control. Treat the output as a trip budget, not an exact bill.

Privacy and how your data is handled

The calculation runs in your browser. The distance, consumption and price you enter are not sent to a server or stored, and refreshing the page restores the defaults.