Fuel Cost Calculator
Distance, consumption, pump price — the trip's fuel bill, live.
How this is calculated
liters = distance ÷ 100 × L/100km · cost = liters × price
Worked example (the defaults): 500 km at 8 L/100km uses 40 liters; at R25 per liter the trip costs R1,000 — R2.00 per km. Split four ways, R250 each. Round trips: enter the total distance (there and back), not one leg.
Making the number more honest
Loaded cars, roof boxes, and 120 km/h cruising all push consumption above the brochure figure — a realistic +15% turns the example's R1,000 into R1,150. And fuel is only the marginal cost: tires, services, and depreciation roughly half-again the per-km figure, which is why official reimbursement rates sit far above pump-math and why "petrol money" chronically underpays the driver.
Frequently asked questions
How is trip fuel cost calculated?
Liters used = distance ÷ 100 × consumption (L/100km); cost = liters × price per liter. A 500 km trip at 8 L/100km uses 40 L — at R25/L that's R1,000.
Where do I find my car's consumption figure?
Most cars show it on the trip computer (average consumption). Manufacturer figures run optimistic — real-world is typically 10–20% higher than the brochure, and highway cruising beats city stop-start. For honest budgeting, use your trip computer's long-term average.
My car shows km/L, not L/100km — how do I convert?
Divide 100 by your km/L figure: 12.5 km/L = 100 ÷ 12.5 = 8 L/100km. (US mpg is another beast: 29.4 mpg ≈ 8 L/100km — lower L/100km is better, higher mpg is better.)
Should I split the cost per person?
The split field divides the total between occupants — the honest way to share a road trip. Fuel is the marginal cost; wear, tires, and depreciation add roughly 30–50% more per km for a full cost picture, which is why reimbursement rates exceed pump math.