Annual Fuel Cost Comparison Calculator

From your annual mileage and each car’s fuel economy, the calculator works out how many litres of fuel each car would use in a year, then multiplies by the fuel price you enter to estimate the annual cost. Monthly cost is simply the annual figure divided by 12, and per-mile and per-kilometre costs divide the annual cost by the distance.

Worked example: at 10,000 miles a year and £1.50 per litre, a car doing 40 UK MPG uses 10,000 ÷ 40 × 4.54609 = 1,136.5 litres, costing about £1,704.78. A car doing 50 UK MPG uses 909.2 litres, costing about £1,363.83 — an annual saving of about £340.96.

Differences are calculated from unrounded values and only then rounded for display, so the saving shown is consistent with the individual figures.

This compares fuel spending only. It excludes the purchase price of the car, depreciation, servicing, road tax, insurance, and any difference in reliability or repair costs — all of which can outweigh fuel savings. A thirstier car that is cheaper to buy and insure may still cost less to run overall.

Real-world consumption can differ from official figures, which are produced under controlled test conditions. Your actual economy depends on driving style, traffic, terrain, load, weather and how well the car is maintained. The prices you enter are your own figures and are not presented as current pump prices.

If you enter an annual distance of zero, the total cost is shown as zero and per-mile and per-kilometre figures are shown as “Not applicable”, since there is no distance to divide by.