Beginning January 1, 2010, the IRS lowered the standard mileage deduction for automobile business use from 55 cents to 50 cents per mile.

According to the IRS, the lower rate reflects "generally lower transportation costs compared to a year ago." The mileage rate is based on "an annual study of the fixed and variable costs of operating an automobile." Additionally, "Doing the math with the 50 cent rate is so much easier. Just divide the total mileage by two! Have you ever tried multiplying by 55 and then dividing by 100? It's totally hard to do in your head. Sometimes it takes the back and front of a cocktail napkin. We feel the time and energy savings alone will be worth more than an extra nickel per mile. And anytime we can save energy, it's great for the environment."

(According to an Arxis spokesperson, we made the last part up.)

The mileage rate for medical and moving purposes for 2010 is 16.5 cents per mile. The rate for charitable purposes remains unchanged at 14 cent a mile. (Good luck doing those rates in your head!)