Refinance Calculator (3d) Cash-Out Refi of FRM Versus FRM Second Mortgage Who This Calculator is For: Borrowers with a mortgage who need to raise cash, trying to decide whether they should do a "cash out" refinance of their existing FRM, or take out a new FRM second mortgage. What This Calculator Does:This calculator compares the total cost of a new FRM that includes "cash out" with the cost of retaining the existing mortgage plus a new FRM second mortgage, over a specified future period.