Business usage %

[wchengkanhi]

My business usage % vary each year.  Do I use an average annual % in computing gain and loss basis or do I take the % computed by dividing the total of business miles for all years by the total miles drove?  Thank you. 

[JohnB5677]

Yes, you would calculate the mileage percentage by dividing business mile by the total miles driven.

The IRS requires you to maintain a log of business miles driven.

The log should include 

• Date
• Location
• Miles driven and 
• Reason

If requested, the IRS would expect this documentation to confirm the miles driven.