Free Australian fuel cost calculator · No sign-up · Runs entirely in your browser
Calculate petrol, diesel, E10 or LPG costs for road trips anywhere in Australia using your distance, fuel consumption and price per litre. This calculator estimates liquid fuel costs only.
| Fuel type | Indicative range |
|---|---|
| Unleaded (ULP 91) | ~$1.72–1.85/L |
| Premium (98 RON) | ~$1.95–2.10/L |
| E10 | ~$1.68–1.80/L |
| Diesel | ~$2.05–2.25/L |
| LPG | ~$1.10–1.20/L |
Indicative defaults only — fuel prices move weekly and vary by region. Enter the price you are actually paying at the pump for an accurate result.
| Item | Value |
|---|
If your last fill-up felt more expensive than usual, you were not imagining it. From 1 July 2026 the temporary fuel-excise relief was reduced from the earlier 32-cent discount to a 16-cent-per-litre discount, which ran through to 2 August 2026. Motorists were still paying less than the standard excise rate — but the effective excise component rose compared with June. Including the GST that applies on top of excise, the ACCC put the total effect at up to 17.6 cents per litre, and it reached the bowser within days.
That coincided with higher international refined fuel prices. In the ACCC's weekly report covering the period to 22 July 2026, average retail petrol across Sydney, Melbourne, Brisbane, Adelaide and Perth reached 179.5 cents per litre, with diesel at 214.9 cents per litre. Diesel has moved harder than petrol because international gasoil benchmarks rose roughly 34 Australian cents per litre over the same period.
Beyond holiday planning, the numbers matter most to commuters weighing up a job further from home, rideshare and delivery drivers working out true cost per kilometre, tradies and sole traders separating business fuel from private, fleet managers comparing petrol against diesel and electric, and buyers testing whether a hybrid's price premium actually pays for itself.
Australia measures fuel economy in litres per 100 kilometres, so every calculation starts by converting that rate into a cost per single kilometre.
| Variable | What it means | Where to find it |
|---|---|---|
| Distance (km) | Total kilometres driven. Double it for a return trip. | Maps app, or your odometer |
| L/100km | Litres consumed per 100 km. Lower is better. | Your trip computer, or the Green Vehicle Guide |
| Price per litre | What you actually pay, not the advertised board price. | Your state's fuel price app |
| Passengers | People splitting the cost. | Your travel group |
The most reliable way to find your own L/100km is to reset the trip meter at a full tank, drive normally for at least 300 km, refill, and divide litres added by kilometres travelled, then multiply by 100. Our fuel economy calculator does that step for you.
Sarah drives 16 km each way to work in Parramatta, five days a week, 46 weeks a year. Her Mazda3 averages 8.5 L/100km and she buys Unleaded 91 at $1.795 per litre.
| Step | Calculation | Result |
|---|---|---|
| Cost per km | (8.5 ÷ 100) × $1.795 | $0.1526 |
| Daily round trip | 32 km × $0.1526 | $4.88 |
| Per week | $4.88 × 5 | $24.41 |
| Annual (7,360 km) | 7,360 × $0.1526 | $1,122.95 |
Just over $1,120 a year in fuel alone — before rego, insurance, servicing, tyres or tolls. That figure is worth knowing when you are weighing up a pay rise against a longer drive. Our salary calculator shows what the extra income is worth after tax, which is the number the commute has to beat.
Four friends drive Sydney to Melbourne and back on the Hume Highway — roughly 878 km each way, so 1,756 km return. The car is a mid-size SUV averaging 9.8 L/100km on the highway. Petrol is $1.795 per litre.
| Step | Calculation | Result |
|---|---|---|
| Litres required | 1,756 × (9.8 ÷ 100) | 172.1 L |
| Total fuel cost | 172.1 × $1.795 | $308.90 |
| Cost per kilometre | $308.90 ÷ 1,756 | $0.176 |
| Split four ways | $308.90 ÷ 4 | $77.22 |
Daniel is a sole-trader electrician who drove 4,200 business kilometres in the 2026–27 year. His diesel ute averages 9.2 L/100km and diesel is running at $2.149 per litre.
| Measure | Calculation | Result |
|---|---|---|
| Fuel cost per km | (9.2 ÷ 100) × $2.149 | $0.1977 |
| Actual fuel spent on business travel | 4,200 × $0.1977 | $830.34 |
| ATO cents-per-km deduction (2026–27) | 4,200 × $0.91 | $3,822.00 |
The cents-per-kilometre method is capped at 5,000 business kilometres per car per year, giving a maximum deduction of $4,550 for 2026–27. If eligible business travel exceeds 5,000 km, it is worth comparing the logbook method — which is better depends on your vehicle costs, business-use percentage and the records you keep. If you are tracking business travel through the year, our guide to business expense tracking and logbooks covers the records the ATO expects to see.
Light and medium rigid trucks sit in a completely different consumption band to passenger vehicles, which is where car-only calculators stop being useful. A delivery operator runs a 650 km route in a medium rigid truck averaging 27 L/100km, with diesel at $2.149 per litre.
| Step | Calculation | Result |
|---|---|---|
| Litres required | 650 × (27 ÷ 100) | 175.5 L |
| Total fuel cost | 175.5 × $2.149 | $377.15 |
| Cost per kilometre | $377.15 ÷ 650 | $0.580 |
| Cost per 100 km | 27 × $2.149 | $58.02 |
At 58 cents per kilometre in fuel alone, a single 10-cent movement in the diesel price changes this run by about $17.55. For operators quoting fixed delivery rates, that is the margin. Heavy vehicles also pay road user charges and are affected by load weight far more than cars — a truck running empty and the same truck at capacity can differ by several litres per 100 km.
Indicative national and Sydney metropolitan averages as at late July 2026. Fuel prices move weekly, so treat these as a starting point rather than a fixed input.
| Fuel type | Indicative price | Notes |
|---|---|---|
| Unleaded 91 (ULP) | ~179.5¢/L | ACCC five-city average, week to 22 July 2026 |
| E10 | ~172¢/L | Cheaper per litre, but ethanol blends consume slightly more |
| Premium 95 | ~191.5¢/L | Required by some European and turbocharged engines |
| Premium 98 | ~199.6¢/L | Only worth it if your manual specifies it |
| Diesel | ~214.9¢/L | ACCC five-city average; more stable than petrol cycles |
| LPG | ~114¢/L | Roughly 25–30% higher consumption than petrol |
| Typical EV charging cost (comparison only) | ~28–35¢/kWh | Not calculated here — shown for context |
| Vehicle type | Typical L/100km | Cost per 100 km | Annual fuel (15,000 km) |
|---|---|---|---|
| Small hybrid (Corolla Hybrid, Yaris Cross) | 3.9–4.5 | ~$7.54 | ~$1,130 |
| Small hatch (Mazda2, i30) | 5.5–7.0 | ~$11.13 | ~$1,670 |
| Medium sedan or SUV (petrol) | 7.5–9.5 | ~$15.26 | ~$2,290 |
| Dual-cab diesel ute (Ranger, HiLux) | 7.6–9.5 | ~$18.27 | ~$2,740 |
| Large SUV / 7-seat 4WD | 10.5–14.0 | ~$21.54 | ~$3,230 |
| Typical EV charging cost (comparison only) | 14–20 kWh/100km | ~$5.10 | ~$765 |
Costs assume ULP at $1.795/L, diesel at $2.149/L and electricity at 30¢/kWh, using the midpoint of each consumption range. Real figures vary with driving style, load, terrain and how much of your driving is urban.
Older Australian drivers, imported vehicles and American review sites all still quote miles per gallon — and there are two different gallons in circulation, which is where most conversion errors come from.
| L/100km | MPG (imperial / UK) | MPG (US) |
|---|---|---|
| 4.0 | 70.6 | 58.8 |
| 5.0 | 56.5 | 47.0 |
| 6.0 | 47.1 | 39.2 |
| 8.0 | 35.3 | 29.4 |
| 10.0 | 28.2 | 23.5 |
| 12.0 | 23.5 | 19.6 |
| 15.0 | 18.8 | 15.7 |
The imperial gallon is 4.546 litres and the US gallon is 3.785 — about 20% smaller. Quoting a US figure as though it were imperial makes a car look considerably thirstier than it is.
Most fuel-saving advice is generic. These are the levers that move real money in Australian conditions.
If you are building these numbers into a household budget, our budget calculator lets you slot the annual figure alongside your other running costs.
How do I calculate fuel cost for a trip?
Divide your fuel consumption in L/100km by 100 to get litres per kilometre, multiply by the price per litre to get cost per kilometre, then multiply by your total distance. For a 500 km trip in a car using 9 L/100km at $1.795 per litre: (9 ÷ 100) × $1.795 = $0.1616 per km, × 500 km = $80.78.
How much fuel will my trip use?
Multiply your distance by your consumption divided by 100. A 500 km trip at 9 L/100km needs 45 litres. Add roughly 10% as a buffer for detours, traffic and the fact that few people run a tank to empty.
What is a good fuel economy figure in Australia?
For a petrol passenger car, anything under 7 L/100km is good and under 5 L/100km is excellent, which in practice means a hybrid. The average Australian passenger car sits around 10–11 L/100km. Diesel vehicles typically achieve 20–35% better economy than an equivalent petrol engine, which partly offsets diesel's higher price per litre.
How much does a Sydney to Melbourne road trip cost in fuel?
The Hume Highway route is roughly 878 km each way. In a car using 9 L/100km at $1.795 per litre, one way costs about $142 and the return trip about $284. A large SUV at 12 L/100km would cost closer to $378 return. Split between four people, a return trip in a mid-size car works out around $70–80 each.
What does L/100km actually mean?
It is the number of litres your vehicle burns travelling 100 kilometres. A car rated at 8 L/100km uses 8 litres every 100 km. Because it measures fuel used rather than distance covered, a lower number is better — the opposite of the MPG figures used in the United States and United Kingdom.
How do I convert MPG to L/100km?
Divide 282.48 by the imperial MPG figure, or 235.21 by the US MPG figure. So 35 imperial MPG equals 8.07 L/100km, while 35 US MPG equals 6.72 L/100km. The gap exists because a US gallon is about 20% smaller than an imperial gallon, so always confirm which measure a source is quoting.
Does driving speed affect fuel consumption?
Considerably. Aerodynamic drag rises with the square of speed, so most petrol cars are at their most efficient somewhere between 80 and 90 km/h. Sustained highway speed uses noticeably more fuel over the same distance than driving at 90 km/h. Electric vehicles are affected more strongly again, because they recover little energy through regenerative braking at constant speed.
Why is my real fuel use higher than the sticker figure?
Manufacturer figures come from standardised laboratory testing under ADR 81/02, without air conditioning, headwinds, roof racks, passengers, hills or traffic. Real-world consumption is routinely higher than the published combined figure, particularly in stop-start city driving. Use your own trip computer average instead — it reflects how you actually drive.
Can I claim fuel costs on my Australian tax return?
You can claim work-related car expenses, but not your ordinary commute between home and work. Under the cents-per-kilometre method the ATO rate is 91 cents per kilometre for 2026–27 (88 cents for 2024–25 and 2025–26), capped at 5,000 business kilometres per car — a maximum of $4,550. That flat rate already includes fuel, registration, insurance, servicing and depreciation, so you cannot claim fuel receipts on top of it. Above 5,000 km the logbook method usually produces a larger deduction.
Is premium fuel worth the extra cost?
Only if your owner's manual specifies a minimum of 95 or 98 RON. Many turbocharged and European engines do. In a vehicle designed to run on 91 RON, premium delivers no measurable economy or power benefit, so the roughly 20 cents per litre extra is simply a higher cost per kilometre. E10 is the opposite trade-off: cheaper per litre but slightly higher consumption, which often makes the two roughly line-ball on cost per kilometre.
Fuel is the running cost most people underestimate, because it is paid in small amounts across the year rather than as one visible bill. With prices moving as sharply as they have through 2026, the highest-value habit is checking your state's fuel app before you fill up rather than after. From there you can compare vehicles with the fuel economy calculator, track distances with the mileage calculator, or look at the full ownership picture with the car loan calculator.