How do you find the IRS mileage rate?

The Internal Revenue Service posts optional standard mileage rates on its website. As of 2015, the rate is 57.5 cents per mile for business purposes, 23 cents per mile for moving or medical purposes, and 14 cents per mile for charitable purposes.

Taxpayers in the United States choose between using standard mileage rates and deducting the actual costs incurred by driving a vehicle for specified purposes, according to the IRS. Rates typically change each year. Charitable rates are set by law, business rates are calculated based on current costs and depreciation, and medical and moving rates are based on variable costs, such as the price of fuel.