There are several ways. First of all, look at your tax return. If you are getting a federal refund it will be on line 20a of your Form 1040. If you owe tax due it will be on line 22.
https://ttlc.intuit.com/questions/1901539-how-do-i-preview-my-turbotax-online-return-before-filing
As you prepare your return there is a "refund monitor" in the upper corner that shows if you are getting a refund or if you have tax due. After you have prepared your return, TurboTax shows you a summary detailing your refund/tax due.