Running Costs
Car Fill-Up Cost by Tank Size in Australia (2026)
Estimate a full tank or partial fill from litres added, tank capacity, pump price and the fuel grade required by your vehicle.
Key points
Key takeaways
Full-tank cost is tank size multiplied by the pump price per litre.
The price gap matters more on a larger fill: 10c/L changes 40 litres by $4 and 80 litres by $8.
Diesel utes and 4WDs can have much larger tanks, so every cent per litre matters more.
Most drivers do not fill from empty, so use litres added when checking a real receipt.
Using this guide
Before you act on the guide
Check the station price, report time and distance before changing your route.
The fill-up cost formula
Multiply the litres you expect to add by the pump price in dollars per litre. If you plan to add 50 litres and the required fuel is $1.85/L, the estimate is 50 x 1.85, or $92.50. Pump prices are shown in cents per litre, so divide by 100 before using the formula.
Example fill sizes
| Litres added | At $1.85/L | At $2.05/L |
|---|---|---|
| 30L | $55.50 | $61.50 |
| 40L | $74.00 | $82.00 |
| 50L | $92.50 | $102.50 |
| 60L | $111.00 | $123.00 |
| 80L | $148.00 | $164.00 |
Tank capacity is not the usual fill amount
The nominal tank capacity comes from the manufacturer for a specific model year and variant. A normal fill is usually smaller because fuel remains in the tank. Use litres added for a receipt check and use the manufacturer capacity only for a full-tank budget estimate.
Why the price gap matters more on larger fills
A 10c/L difference changes 40 litres by $4, 60 litres by $6 and 80 litres by $8. Use the litres you expect to buy when deciding whether a lower-priced station is worth the detour.
Use the correct fuel grade
Check the owner's manual or fuel-flap label. If the vehicle requires P95, P98 or diesel, do not estimate the fill with a cheaper U91 or E10 price. Tank capacity can also differ between variants, so confirm both inputs for the exact vehicle.
Check the current local price
Search your suburb, select the required fuel grade and compare nearby station prices and update times. Confirm the final price at the bowser before filling.
Common questions
Frequently asked questions
Multiply your tank size in litres by the price per litre. For a real top-up, multiply the litres added by the pump price on the receipt.