How much will your trip cost in fuel?

What the Fuel Cost Calculator Does

This Fuel Cost Calculator estimates the total fuel cost of a trip from three inputs: the distance you plan to drive, your vehicle's fuel consumption, and the current price of fuel. Enter those numbers and you get a single trip cost figure you can use for budgeting.

It is built for everyday drivers planning a road trip, commuters comparing routes, rideshare and delivery drivers tracking expenses, and anyone splitting fuel costs with passengers. It works for petrol, diesel, or any liquid fuel sold by the liter, since the math is the same.

How It Works: The Fuel Cost Formula

The calculator uses the standard European consumption format, liters per 100 kilometers (L/100 km), and applies a direct formula:

Cost = (Distance / 100) x Consumption x Price per Liter

First, distance divided by 100 tells you how many 100-km blocks you are driving. Multiplying that by your consumption gives the total liters burned. Multiplying liters by the price per liter gives the total cost. You can rearrange the same equation to find fuel used alone: Liters = (Distance / 100) x Consumption.

Worked Example With Real Numbers

Suppose you drive 420 km, your car averages 7.5 L/100 km, and fuel costs 1.80 per liter.

Step 1 - 100-km blocks: 420 / 100 = 4.2. Step 2 - liters used: 4.2 x 7.5 = 31.5 liters. Step 3 - total cost: 31.5 x 1.80 = 56.70.

So the trip costs 56.70 in fuel. If three people split it evenly, that is 18.90 each. A round trip would simply double the distance to 840 km, giving 113.40.

Tips and Common Mistakes

Small input errors change the result a lot, so check your units and figures before trusting the number.

• Match your units: this tool expects L/100 km. If your data is in miles per gallon (mpg), convert first or you will get a wrong answer.
• Use real-world consumption, not the manufacturer's lab figure. Check your trip computer's long-term average or calculate it from past fill-ups.
• For a return journey, enter the total round-trip distance, not the one-way distance.
• Update the price per liter to the current pump price; fuel prices shift week to week and by region.
• Add a buffer for detours, traffic, and refueling stops, which all raise actual cost above the estimate.

Factors That Affect Your Real Fuel Cost

The formula is exact, but the consumption figure you feed it is an average. Actual fuel use rises with higher speeds, heavy acceleration and braking, a loaded vehicle or roof box, uphill terrain, cold weather, and running the air conditioning.

City driving with frequent stops usually burns more per 100 km than steady highway cruising. Underinflated tires, an overdue service, and a heavy right foot also push consumption up. For the most reliable estimate, use a consumption value measured over the kind of driving your trip actually involves.