Here is a sample of calculations, used to figure out the price for fuel for the year so if you have clients who are self-employed, theyβll have the number of mileage that they drove for the year, and the cost of the fuel. NOTE: you cannot claim both actual expenses and mileage for the same vehicle - Total miles: 13,073 miles - Fuel economy assumption: 27 mpg - Gallons used = 13,073 Γ· 27 β 484 gallons - Cost per gallon: $3.07 - Annual fuel cost β 484 Γ $3.07 β $1,486