From Primary Residence to Rental - Tax Implications?

[Jackie F.]

I know I can ask my tax accountant, but wanted to get a general feel for what I am thinking of doing.

This home was my primary residence for 3+ years then it became a rental for the past 1.5 years.

How does the capital gains tax work?  This is in case I decide to NOT use a 1031 exchange, which is still an option.  But if I simply want to cash out my profits, how much is taxable?