How to Calculate Your True Commuting Cost Per Kilometer in Australia

The Hidden Price of Your Daily Drive

As we navigate June 2026, Australian motorists are feeling the pinch. Global tensions in the Middle East have caused significant ripples in international oil markets,, and the temporary halving of the federal fuel excise is slated to expire on 30 June 2026,. With bowser prices fluctuating wildly, understanding your true commuting cost per kilometre has never been more vital for your household budget.

Many drivers simply look at the price board at their local servo and calculate their fuel spend. However, the true cost of commuting encompasses far more than just petrol or diesel. When the Australian Taxation Office (ATO) sets its cents-per-kilometre rate for vehicle deductions—currently sitting at 88 cents for the 2025–2026 financial year,—it factors in fuel, registration, insurance, servicing, depreciation, and wear-and-tear. But what is your personal cost per kilometre?

Step 1: Calculating Your Fuel Cost Per Kilometre

The foundation of your commuting cost is your fuel consumption. To calculate this, you need your vehicle's average fuel economy (measured in litres per 100km) and the current price of your preferred fuel.

Let's look at the current national landscape. As of June 2026, Unleaded 91 (U91) prices currently range from 120 cpl to 166.7 cpl nationally, a difference of 38.9%. The national average sits at 151.6 cpl.

If your car consumes 8L/100km, and you are paying the national average for U91, your calculation is: (8 / 100) x $1.516 = $0.12 per kilometre.

Step 2: Factoring in Your Location and Fuel Type

Your true cost is heavily influenced by where you live and what you drive. Our latest data reveals massive regional disparities across Australia:

• Capital City Savings: Adelaide currently offers the cheapest prices for 4 different fuel types, making it Australia's most affordable capital city for motorists. The top 3 cheapest capital cities for Unleaded 91 are currently Adelaide (158.43 cpl), Sydney (161.42 cpl), and Perth (163.45 cpl).
• Regional Penalties: Unleaded 91 prices are 10.6% higher in Townsville (175.22 cpl) than in Adelaide (158.43 cpl).
• Diesel Discrepancies: Diesel is currently 12.1% more expensive in Hobart (214.8 cpl) compared to Newcastle (191.7 cpl).
• Premium Petrol: Premium 98 prices vary significantly across Australia, with Darwin (202.64 cpl) being 10.5% more expensive than Adelaide (183.43 cpl). In Sydney, Premium 95 (178.26 cpl) costs 10.4% more than Unleaded 91 (161.42 cpl).

If your vehicle can handle alternative fuels, there are savings to be found. Brisbane motorists can save 1.4% by choosing E10 (164.48 cpl) over Unleaded 91 (166.85 cpl). Meanwhile, LPG (avg. 108.5 cpl) remains 28.4% cheaper than Unleaded 91 (avg. 151.6 cpl), offering significant savings for vehicles with dual-fuel capability. On the extreme ends of the spectrum, transitioning to an EV (avg. 45 cpl) slashes commuting costs drastically, especially when compared to heavy-duty alternatives like B20 (avg. 289.9 cpl), which is 544.2% more expensive than EV charging.

Step 3: Adding Fixed and Variable Running Costs

To find your true cost per kilometre, you must add your fixed expenses (rego, insurance, depreciation) and variable non-fuel expenses (servicing, tyres).

1. Total your annual fixed costs: Add your yearly rego, comprehensive insurance, and estimated annual depreciation. For a standard hatchback, this might total $3,500 a year.
2. Total your variable running costs: Add your yearly servicing, tyre replacements, and maintenance. Let's estimate $1,000 a year.
3. Divide by annual kilometres: If you drive 15,000 km a year, your non-fuel cost is $4,500 / 15,000 = $0.30 per kilometre.

Add this to your fuel cost ($0.12 per km), and your true commuting cost is $0.42 per kilometre. Suddenly, that 40km daily round trip to the centre of town is costing you nearly $17 a day, or over $4,000 a year!

Expert Tips to Reduce Your Commuting Costs

With the government fuel excise relief winding down, proactive behaviour is essential to keep your transport budget in check.

• Optimise Your Route and Driving Behaviour: Avoid heavy acceleration and hard braking. Smooth driving on freeways rather than stop-start suburban streets can improve fuel economy by up to 20%.
• Keep on Top of Maintenance: Under-inflated tyres increase rolling resistance, forcing your engine to work harder and burn more petrol. Regular servicing ensures your engine runs efficiently.
• Never Pay More Than You Have To: As we've seen, U91 prices can vary by almost 40% depending on where you fill up. Relying on real-time data to find the cheapest servos along your route is the easiest way to instantly lower your cost per kilometre.

Take Control of Your Commute with FuelRadar

Calculating your true commuting cost is the first step toward better financial health. The next step is actively reducing it. While you can't control rego or insurance rates easily, you can absolutely control what you pay at the bowser.

This is where FuelRadar comes in. Designed for Australian drivers, FuelRadar provides real-time fuel prices Australia-wide, helping you find the cheapest fuel nearby, no matter what you drive. Whether you're hunting for affordable diesel in Hobart or the cheapest E10 in Brisbane, you can analyse local trends and make informed decisions.

Available on both iOS and Android, FuelRadar puts the power back in your hands. Check out our interactive fuel map today and start driving your cost per kilometre down.