WASHINGTON — The Internal Revenue Service today issued the 2012 optional standard mileage rates used to calculate the deductible costs of operating an automobile for business, charitable, medical or moving purposes.

The standard mileage rates are based upon information compiled annually by Runzheimer International, an independent contractor to the IRS.

Although taxpayers have the choice of deducting either actual expenses or taking the standard mileage rate, the latter is usually chosen because it is not only simpler, but often provides a greater deduction.

Beginning on Jan. 1, 2012, the standard mileage rates for the use of a car (also vans, pickups or panel trucks) will be:

• 55.5 cents per mile for business miles driven
• 23 cents per mile driven for medical or moving purposes
• 14 cents per mile driven in service of charitable organizations

The rate for business miles driven is unchanged from the mid-year adjustment that became effective on July 1, 2011. The medical and moving rate has been reduced by 0.5 cents per mile.

The standard mileage rate for business is based on an annual study of the fixed and variable costs of operating an automobile. The rate for medical and moving purposes is based on the variable costs as determined by the same study. Independent contractor Runzheimer International conducted the study.

Taxpayers always have the option of calculating the actual costs of using their vehicle rather than using the standard mileage rates.

A taxpayer may not use the business standard mileage rate for a vehicle after using any depreciation method under the Modified Accelerated Cost Recovery System (MACRS) or after claiming a Section 179 deduction for that vehicle. In addition, the business standard mileage rate cannot be used for more than four vehicles used simultaneously.

These and other requirements for a taxpayer to use a standard mileage rate to calculate the amount of a deductible business, moving, medical or charitable expense are in Rev. Proc. 2010-51.

Notice 2012-01 contains the standard mileage rates, the amount a taxpayer must use in calculating reductions to basis for depreciation taken under the business standard mileage rate, and the maximum standard automobile cost that a taxpayer may use in computing the allowance under a fixed and variable rate plan.