How do you see your tax amount after Turbo tax takes deductions out?

Just to clarify, are you trying to preview your tax return before you file or are you trying to see the amount of your refund?

You can view your entire return or just your 1040 form before you e-file:

Open or continue your return.
Select Tax Tools in the left menu (if you don't see this, select the menu icon in the upper-left corner).
With the Tax Tools menu open, you can then:
Select Print Center and then Print, Save, or Preview This Year's Return to preview your entire return, including all forms and worksheets (you may be asked to register or pay first).
View only your 1040 form by selecting Tools. Next, select View Tax Summary in the pop-up, then Preview my 1040 in the left menu
 

Please click this TurboTax Help link to watch a video to help walk you through the steps. 

How do I preview my TurboTax Online return before filing?