Yes. You can deduct your taxes by entering them in as Expenses. Add an Expense Category named Taxes or any other item you'd like to track from the Settings page.
NOTE: They are not calculated for you.
As you will probably enter your taxes from your paycheck to make sure you're tracking accurately please follow one of these methods.
Enter your full amount daily to include hourly. Enter a Paycheck to include only your deductions from your paycheck. Include taxes and anything else that is taken from your paycheck. Enter 0 for the Tip and Hours fields. This allows you to see which days are more profitable.
Enter what you went home with daily. Do not enter your hourly wage daily. Enter your paycheck total earnings and deductions. This will show you how you earning and take home money each day. Please note doing it this way you won't see how each day compares to each other as you're moving the Credit Card Tips to your paycheck.