Can I use TurboTax to help file my 2018 quarterly estimated taxes?

[Critter]

Yes you can fill out the 1040ES quarterly slips but you can not pay it though Turbo Tax.  

You can just type W4 in the search box at the top of your return , click on Find. Then Click on Jump To and it will take you to the estimated tax payments section. Say no to changing your W-4 and the next screen will start the estimated taxes section.

OR
To prepare the quarterly estimated tax forms 1040ES for next year go to
Federal Taxes or Personal (H&B version)
Other Tax Situations
Other Tax Forms
Form W-4 and Estimated Taxes - Click the Start or Update button 

Or here are the 1040ES instructions and blank forms
http://www.irs.gov/pub/irs-pdf/f1040es.pdf 

The 1040ES quarterly estimates for 2016 are due April 18, June 15, Sept 15 and Jan 17, 2017.  Your state will also have their own estimate forms. You mail in the estimates with a check or you can do it electronically at the IRS and maybe your state.
 
 If you didn't owe or missed making the prior quarterly estimated payments and need to just calculate starting now, you can go though the Estimated Taxes section and just put $1 (one dollar) in for the quarters you missed.  Then it will only figure the current and remaining quarters.