The Internal Revenue Service announced the 2013 optional standard mileage rate for calculating the deductible costs of operating an automobile for business purposes. Starting January 1, 2013, the standard mileage rate for the business use of a car, van, pickup, or panel truck will be 56.5 cents per mile for business miles driven. This rate is one cent per mile above the standard mileage rate in effect for 2012. Taxpayers can choose between the standard mileage rate or their actual costs to calculate their deduction for the business use of a vehicle. November 21, 2012.