|Always saw someone asked about if they need to do refinance, I have the rough idea that as long as the rate is lower and it is no cost refinance and you got time on your side, you will benefit, but never really calculate to prove it. Here since someone asked again, i just did some example.
400K loan, started with 5% on 6/30/2000, monthly pay :2147, for the last 10 years.
Now 10 years later, we will have Principal = 324576
If stay with 5% rate, and pay 2147 monthly, it will pay down on 6/30/2030.
If refinance with 4.75%, and still pay 2147 monthly,it will pay down on 9/30/2029, almost 1 year earlier.
If refinance with 4.5%, pay same 2147, paydown on 2/20/1029, abuot 1 and 1/2 years earlier.
Even with 4.875, you can still pay down half year earlier on 1/30/2030.
So, depends on your situation, you may think lower .25% is worth a refinace, or someone might think .5% is worth it. but as long as rate is lower and no cost, you will save money.