Fixed or Variable - Tools to help calculate?

[Matt W.]

Does anyone have a formula they use when determining what type of loan to take? I understand much of the loan savings and interest rate calculations are conjecture, but given our current political climate, fed policy, and economy in general, what are borrowers deciding at this point?

Some background: I am helping source loans, some under $1M, some between $1M-$3M for multifamily apartment buildings (10-40 units usually). Chase is currently offering 3, 5, 7 year fixed, currently in the 4.3% to 4.5% ranges depending on initial fixed term  OR variable rate starting around 3.4%, adjusted every 6 months based on 12-MTA + 2.65% margin.  

Thanks for any thoughts or insight.