How to estimate refinance on multi unit?

[Kate Hensley]

Hi Bigger Pockets People! 

I am renovating a duplex and am currently working through how much to invest (how nice to make it) in it as either a rental property or an Air BnB in Colorado Springs. 

Do any of you have any tips or information on how to best calculate a refinance of a multi unit? I am in the process of running the numbers to maximize profit while pulling out the most possible funds for the next deal. 

Thank you!

Kate