Will turbo tax calculate the depreciation of our rental home if we sell it? Is there a way to pre-calculate the capital gains tax (estimate)?

Presumably you've been entering your rental activity each year using TurboTax's "Rental Properties and Royalties (Sch E)" all along.  If that'e the case and you use that same interview in the year of the sale, then yes TurboTax will calculate the accumulated depreciation to the time of the sale and that depreciation will be included for determining "gain".

If you're using a desktop version of TurboTax you can make estimates of the tax associated with the sale - depreciation recapture plus capital gain - using TurboTax's "What if" worksheets.  This function is not available in the online product, as I understand it.

However, you should be able to make a rough calculation of taxes associated with the sale by looking at your 2018 "Depreciation and Amortization Report".  Add together the basis of the property, (structure and land) and subtract from that number the sum of the "Prior Depreciation" and "Current depreciation) to come to a net basis figure.  Subtract this net basis figure from your estimate of the selling price net of selling fees to come to an overall gain figure.

The total amount of depreciation will be "recaptured" and taxed at "ordinary" tax rates up to a maximum of 25%.  Use the 25% figure as a conservative estimate.  The rest of the gain over and above the recaptured depreciation will be taxed at capital gain rates.  Long term capital gain rates run from 0% to 20% depending on your overall income.  You could use 15% as a good and presumably reasonable rate here.

Tom Young