Free Australian petrol and fuel calculator. Figure fuel cost for any trip, work out litres per 100 km, km per litre, fuel efficiency, fuel usage and petrol cost per km in seconds. Live NSW fuel prices auto-loaded — supports ULP91, ULP95, ULP98, E10, Diesel, Premium Diesel & LPG.
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Enter how many litres you used and how many kilometres you drove. Great for working out your real-world fuel consumption after a tank fill-up.
Convert between L/100km (Australian standard) and km/L. Type into either field — the other updates automatically.
Work out the petrol cost per km for any vehicle and fuel price.
Fuel usage estimator — find out how many litres of petrol you'll need for a planned trip and what it'll cost.
To compute gas cost (or petrol/diesel cost) for any trip in Australia, you need three numbers: trip distance in km, your vehicle's fuel consumption in L/100km, and the current fuel price per litre. Here's the simple Australian fuel cost formula:
L/100km is the standard fuel-consumption measure in Australia. To work out litres per 100 kilometers:
Many drivers prefer km per litre. To convert from L/100km to km/L (or work it out from a tank fill):
To work out cost of petrol per km, convert your consumption to litres-per-km and multiply by price:
For Australian vehicles, expect roughly:
Use these as starting points in the fuel consumption calculator if you don't know your exact L/100km. Real-world figures vary with driving style, load and conditions.
| Vehicle class | Typical L/100km | km/L | Cost/km @ $1.95 |
|---|---|---|---|
| Small hatch (Yaris, Mazda 2) | 5.5 | 18.2 | $0.107 |
| Compact SUV (CX-3, HR-V) | 6.8 | 14.7 | $0.133 |
| Mid sedan (Camry hybrid) | 4.7 | 21.3 | $0.092 |
| Mid sedan (Camry petrol) | 7.8 | 12.8 | $0.152 |
| Mid SUV (RAV4, CX-5) | 8.5 | 11.8 | $0.166 |
| Large SUV (Prado, MU-X) | 10.5 | 9.5 | $0.205 |
| Diesel ute (Ranger, Hilux) | 8.5 | 11.8 | $0.166 |
| Petrol ute V6 | 11.5 | 8.7 | $0.224 |
| Van (HiAce, Transit) | 10.5 | 9.5 | $0.205 |
| Light truck | 15.0 | 6.7 | $0.293 |
Once you know your numbers from the fuel spend calculator, here's how to cut them.
Dropping highway speed by 20 km/h can cut fuel use 15–20%. Worth $300–500/year for the average Aussie commuter.
Under-inflated tyres add 3–5% to fuel use. Inflate to the placard pressure on the door jamb.
NSW prices swing 30–50¢/L over a cycle. Filling on the cheap day saves $15–25 per tank.
Hard launches and braking burn 20–30% more fuel in city driving. Anticipate traffic.
Every 50 kg adds ~2% to consumption. Roof racks add 10–25% on the highway — remove when not in use.
Don't pay for 98 if your car is rated for 91. Check the fuel-flap label — premium gives no benefit on lower-spec engines.
Multiply trip distance (km) by fuel consumption (L/100km), divide by 100 for litres used, then multiply by the price per litre. Our calculator above does it instantly with live NSW fuel prices.
L/100km = (litres used ÷ km driven) × 100. Example: 42 L over 500 km = 8.4 L/100km. Use the L/100km Calculator tab above.
km/L = km driven ÷ litres used. Or convert from L/100km: km/L = 100 ÷ L/100km. So 8 L/100km = 12.5 km/L.
Divide 100 by your L/100km figure. A car at 6 L/100km does 100 ÷ 6 = 16.7 km/L.
Cost per km = (L/100km ÷ 100) × price per litre. The Cost per KM tab calculates this automatically with live prices.
Use the formula above with current Australian fuel prices. The national average is ~$1.95/L for ULP91 and ~$2.00/L for diesel in late 2025.
Typical Australian passenger cars use 0.06–0.10 L/km. Small cars sit near 0.06, sedans 0.07–0.08, and SUVs/utes 0.09–0.12 L/km.
Fill the tank, reset the trip meter, drive normally, refill, then divide litres added by km driven and multiply by 100 for L/100km. Lower = more efficient.
Add up litres used and km driven over several tanks, then apply (total L ÷ total km) × 100. Multi-tank averages are more accurate than a single fill.
Use the Fuel Usage Estimator tab — enter distance and your L/100km, and it shows litres needed plus the cost.
Modern car trip computers usually display L/100km directly. To verify, divide tank litres by trip km and multiply by 100 — should match within ±5%.
Towing typically adds 30–60% to L/100km. Multiply your normal consumption by 1.4–1.6 as a starting estimate, then refine after a tank.
Yes — designed for Australian drivers using L/100km, km/L, AUD per litre and live NSW FuelCheck data. Works for all states.
Yes. Prices auto-load from the NSW Government FuelCheck API every 30 minutes. You can override with a manual price for any state or station.
Yes — for multi-vehicle fleet calculations with savings projections, try our dedicated Fleet Fuel Cost Calculator.