That"s true, pretty much nobody stays in one home for 30 years to pay it off anymore, so that may be a calculation that doesn"t really apply to a lot of people. Just make sure there"s no chance that you guys would up and move next year or something, you"ll more than likely have less equity in your home after you start up this new 30 year loan than you do now. The one main figure I keep in mind whenever thinking about a refinance, 30 yr vs 15 year etc is that I want to make sure my home is paid off by the time I"m 60, regardless of monthly payment figures and such. I don"t want to go into retirement with a house payment. Right now I"m 34 with 25 years left on my current mortgage, and while theres a good chance we won"t be in this same house when I retire, if we do make the decision to move, it"ll probably be with a 15 year loan if I"m over the age of 40 at that point.