Fuel Cost Calculator: How to Calculate the Exact Cost of Any Trip

Before a long road trip, knowing your fuel cost helps you budget properly. And understanding your car's actual cost per kilometre reveals whether upgrading to a more efficient vehicle actually saves money. Here's everything you need to know.

The Fuel Cost Formula

Average Fuel Efficiency by Vehicle Type

How to Improve Fuel Efficiency

• Maintain proper tyre pressure — underinflated tyres increase rolling resistance
• Remove excess weight — every extra 45kg reduces efficiency by about 1–2%
• Drive at consistent speed — highway speeds of 90–100km/h are most efficient for most cars
• Avoid hard acceleration and braking — smooth driving saves 15–30% fuel
• Use air conditioning wisely — AC increases fuel use by 5–25% depending on conditions
• Keep engine maintained — dirty air filters and old spark plugs reduce efficiency

Real Cost Per Kilometre

Fuel is only part of the cost of driving. A complete picture includes fuel + maintenance + insurance + depreciation + financing. For most mid-range vehicles, the true all-in cost runs $0.25–$0.45 per kilometre, with fuel typically making up 30–40% of that total.

FAQ

How do I find my car's actual fuel efficiency?

Fill up completely, reset your trip odometer, drive normally until near empty, fill up again. Divide the kilometres driven by the litres used to refill. This gives your real-world efficiency, which is often 10–15% lower than the manufacturer's claimed figure.