Calculate the exact fuel cost of any trip — total cost, litres or gallons needed, and CO2 emissions.
Enter a distance and fuel price above, then add both vehicles' efficiencies to compare trip costs.
The basic formula is simple: Fuel needed × Price per unit = Trip cost. The fuel needed depends on your vehicle's efficiency and the distance driven.
Burning fuel releases CO₂ proportional to the volume consumed. Petrol produces approximately 2.31 kg CO₂ per litre and diesel produces 2.68 kg CO₂ per litre. These are standardised values used by environmental agencies.
Divide the total trip cost by the distance. For example, if a 300 km trip costs $35, the cost per km is $35 ÷ 300 = $0.117 per km. The calculator shows this automatically in the results.
A modern petrol car averages 6–8 L/100km (35–47 MPG). Diesels typically achieve 5–7 L/100km. Hybrids and economy cars can reach 4–5 L/100km. SUVs and pickup trucks usually consume 10–14 L/100km (17–28 MPG).
Divide 235.21 by the MPG value. Example: 35 MPG = 235.21 ÷ 35 = 6.72 L/100km. To convert back, divide 235.21 by L/100km.
Yes — assuming the same route and conditions. Enable the Round trip toggle in the calculator to automatically double the distance and recalculate all results.
A 100 km trip in a car consuming 8 L/100km uses 8 litres of petrol, producing approximately 8 × 2.31 = 18.5 kg of CO₂. Over a year of typical driving (15,000 km), the same car emits around 2.8 tonnes of CO₂.