Straight-Line, Half-Year Short-Year Calculation

Because this method uses a half-year convention, the half-year rule applies. The depreciation is calculated as if the asset were placed in service or disposed of during the middle of the short tax year. For example, if an asset were placed in service during a short tax year of 3 months, the annual depreciation would be one-half of the 3-month depreciation deduction. The formula is: