You can calculate bad debt expenses by adding up your monthly credit card payments, auto loan payments, and any personal loan payments. (debtfirms.com)
By dividing your total monthly debt expenses by your total monthly income, you end up with your debt to income ratio. (secureloanconsolidation.com)
For example, you could not claim a personal bad debt expense for your neighbor not paying you for taking care of his pets while he was on vacation. (smallbusiness.chron.com)