The standard mileage rate is a fixed amount that the IRS allows taxpayers to deduct for each mile driven while conducting business or traveling for charitable purposes. It is intended to provide an easy way to calculate and claim deductions related to vehicle expenses, without having to keep track of actual costs such as gasoline, oil changes, insurance premiums, and depreciation. The rate varies depending on the purpose of the trip (business, medical, or moving) and is adjusted annually for inflation.