I have sold my rental property in 2019. How can is estimate the amount of capital gains I will need to pay when the 2019 taxes are filed.

I have sold my rental property May 2019. I want to estimate the amount of funds that I will need to send to the IRS so that the funds are available to send to the IRS.  All taxes from when the home became a rental in 2009 have been filed with turbo tax.