To work out the cost of a fill-up, multiply the litres you actually fill by the price per litre. As an example using prices effective from 1 July 2026, filling 50 litres of 95 unleaded at the Gauteng benchmark of R26.10 per litre costs about R1,305. Use the calculator below and enter the current price for your fuel grade and area.
This guide is part of our South African Fuel Prices hub.
The simple formula
Litres to fill × price per litre = estimated total. Your tank capacity is the most the tank can hold, while the litres you actually need is the amount to fill from the current level, so the two are not always the same. As an example using prices effective from 1 July 2026, a 45-litre fill of 93 unleaded at the Gauteng benchmark of R25.94 costs about R1,167.30, and a 50-litre fill of 95 unleaded at R26.10 costs about R1,305.00.
Fuel cost calculator
The default example uses the Gauteng petrol-95 benchmark effective from 1 July 2026. Replace it with the price shown at your filling station for a more accurate estimate.
Enter the litres you actually want to fill (this may be less than your tank capacity) and the price per litre, then choose Calculate cost.
Tips for an accurate estimate
- Use the current price for your fuel grade and area — petrol prices are set per zone, so Gauteng and coastal benchmarks differ.
- For diesel, use the price shown at the pump, because retail diesel prices are not regulated and vary by station.
- Enter the litres you actually need, which may be less than your full tank capacity.
- Fuel prices are normally adjusted on the first Wednesday of each month, so update the price after each adjustment.
For the latest figures, see our current petrol and diesel prices guide, and inland vs coastal fuel prices to understand regional differences.
Frequently asked questions
How do I calculate the cost of a fill-up?
Multiply the litres you actually fill by the price per litre. For example, 50 litres at R26.10 per litre is about R1,305. The litres you need may be less than your tank capacity, depending on how much fuel is already in the tank.
How much does it cost to fill a 50-litre tank?
As an example using prices effective from 1 July 2026, 50 litres at the Gauteng petrol-95 benchmark of R26.10 per litre is about R1,305. The cost changes when the fuel price is adjusted.
Why does a fill-up cost more inland than at the coast?
Inland benchmark prices are higher than coastal benchmark prices because of the transport differential added by zone, so the same number of litres costs more inland.
Does the fuel cost calculator work for diesel?
Yes. Enter the litres and the price per litre you are charged at the pump. Diesel retail prices are not regulated and vary by service station, so use the price shown at the pump.
Official sources
- Department of Mineral and Petroleum Resources (DMPR): fuel prices
- DMPR media statement: fuel prices effective 1 July 2026
- Fuels Industry Association of South Africa: current and past fuel prices
Verification and sources
Verification note: This guide was independently fact-checked against official support documentation. Learn more about our Editorial Policy & Financial Review Board and how our corporate finance team ensures accuracy and safety for South African consumers.