The IRS announced last week (IR-2012-95) a penny per mile increase in the standard mileage rate for business and medical or moving purposes.
For business purposes, the rate increases from 55.5 cents per mile to 56.5 cents per mile (don't ask me why they do not round it to the nearest penny).
For medical or moving purposes, the rate increases from 23 cents per mile to 24 cents per mile.
The charitable rate remains at 14 cents per mile.
The business rate is based on an annual study of the fixed and variable costs of operating an automobile. Taxpayers have the option of calculating the actual costs of using their vehicle rather than using the standard mileage rates ( I would guess that most farmers use this method rather than the standard mileage rate).