About the Fuel Cost calculator
Work out your petrol cost per kilometre and monthly fuel cost with this fuel cost calculator for South Africa. Enter a trip distance, your car’s consumption and the pump price to see the cost per trip, per period and per year.
How the Fuel Cost calculator works
Fuel used per trip is the distance multiplied by your consumption in litres per 100 km. Multiplying by the fuel price gives the Rand cost per trip.
Costs are then scaled by the number of trips per period you choose — day, week, month or year. A daily commute is treated as roughly five trips a week; weekly, monthly and yearly periods use 52, 12 and 1 multiplier respectively.
The default fuel price (R22 per litre) is a bundled estimate from Department of Mineral Resources and Energy (DMRE) official fuel price publication — always replace it with your local pump price, since South African fuel prices change monthly.
The Fuel Cost calculator formula
- Litres per trip
distance (km) × consumption (L/100km) ÷ 100- Cost per trip
litres per trip × fuel price per litre- Cost per period
cost per trip × trips per period- Annual cost
cost per trip × trips per period × periods per year
Worked example
A driver commuting 30 km per trip in a car using 7.5 L/100km, making 20 trips a month at the default fuel price.
A 30 km commute, 20 trips a month
| Trip distance | 30 km |
|---|---|
| Fuel consumption | 7.5 L/100km |
| Fuel price | R 22,00 |
| Trips per period | 20 |
| Period | Month |
Results
- Cost per period
- R 990,00
- Cost per trip
- R 49,50
- Annual cost
- R 11 880,00
- Litres per trip
- 2,25
- Annual litres
- 540,00
Key terms
- L/100km
- Litres of fuel used to travel 100 km — the standard consumption measure in South Africa. Lower is better.
- Petrol cost per km
- The fuel price multiplied by your consumption, divided by 100. Useful for comparing cars or quoting travel costs.
- Pump price
- The regulated retail price of petrol or diesel per litre, adjusted monthly by the DMRE based on the Rand and oil price.
Frequently asked questions
How do I calculate petrol cost per km?
Multiply your consumption (L/100km) by the fuel price and divide by 100. For example, at 7.5 L/100km the calculator shows the per-trip and per-period cost automatically.
Which fuel price should I use?
Use your local pump price. The default of R22/L is a bundled estimate and South African fuel prices change monthly.
Does the calculator work for diesel cars?
Yes — just enter the diesel price per litre and your car’s consumption figure.
How is the monthly fuel cost worked out?
Monthly cost = distance per trip × consumption ÷ 100 × fuel price × number of trips per month.