[fnovd]

>A house at $250k at a 3.5% interest rate would cost you $72k in interest on a 15-year mortgage or $154k in interest on a 30-year mortgage. At that point, it is worth sending additional payments (especially early on in the mortgage) to save on interest.

I would argue that it's not necessarily a smart idea to pay extra just to avoid interest. $154k looks like a lot, and it is, but it's still just paying interest at 3.5%. On average, you'll do better to put that money into investments. Additionally, the ~$1k you're paying every month is a lot less in year 20 than it was in year 1 due to inflation. Your mortgage payments, inflation adjusted, are actually going down every year.

[dlubarov]

And depending on your tax situation, the effective loan rate might be 3.5% * (100% - marginal tax bracket) after deducting interest payments.