For the tax year 2023, the standard mileage rate for charitable contributions is 14 cents per mile. To calculate the deductible amount for Houtan's 400 miles driven for volunteer work, you can use the following formula:
Deduction = Miles driven × Standard rate
In this case:
Deduction = 400 miles × $0.14/mile = $56.00
Therefore, Houtan can deduct $56.00 as a charitable contribution on his Schedule A (Form 1040), Itemized Deductions.