Fuel Cost Per Mile Calculator

How it is calculated

Fuel economy is entered in miles per gallon (MPG) and the price per gallon. The tool divides: cost per mile = price per gallon ÷ MPG, and cost per 100 miles = cost per mile × 100. The logic is that one gallon carries you MPG miles, so each mile uses 1 ÷ MPG of a gallon and costs that share of the price. Both results are rounded to two decimals in the tool's default currency, so a cost per mile of a few cents is shown only to the cent. The 100-mile figure holds more detail for comparisons. An MPG of zero or below, or a negative price, gives no result; a zero price gives zero cost.

Common mistakes

• Entering litres per 100 km in the MPG field. The two scales run in opposite directions, so a thrifty car with 5 L/100 km would look like a gas guzzler at 5 MPG.
• Mixing US and imperial gallons. An imperial gallon is larger than a US gallon, so the MPG figure and the price per gallon must use the same gallon.
• Multiplying the rounded $0.13 per mile by a long distance. The rounding to cents costs you a couple of dollars over 500 miles; use the cost per 100 miles figure instead.
• Using a car's rated MPG while mostly driving short city trips with a cold engine, where real economy is usually lower.
• Treating the figure as the full cost of driving. It counts fuel only, not maintenance, tyres, insurance or depreciation.