A Sole Proprietor's business use of a car or truck is claimed on line 9 and Part IV of Form 1040, Schedule C (PDF), Schedule C, Profit or Loss from Business or, if eligible, line 2 of Form 1040, Schedule C-EZ (PDF), Net Profit from Business. You may use either the actual expense method in calculating your car or truck expense or, if eligible, the standard mileage rate but not both. Depreciation expense is already included in this standard mileage rate. Depreciation is only calculated as a separate expense when using the actual expense method. Deductible employee business use of a car or truck may be taken on Form 2106 (PDF), Employee Business Expenses , or if, eligible, line 1 of Form 2106-EZ (PDF), Unreimbursed Employee Business Expenses. The car and truck expenses are then taken with other employee business expenses on line 20, Form 1040, Schedule A&B (PDF) Itemized Deductions. For more information, refer to Publication 463, Travel, Entertainment, Gift, and Car Expenses, and Publication 535, Business Expenses .