100k at 15yr and 6% interest with monthly payments, the total paid back is $151,894.23 - the amount over 100k was interest.
100k at 30yr and 6% interest? Total paid back is $215,838.19 - more than twice the total interest paid back.
Also you’re correct about the higher cost of the mortgage, and this doesn’t really work as well at 6%… but if you had a 3% mortgage, you would have better returns taking the 30 year and investing the difference each month. The amount of money you’d make from the returns on that would, on average, be greater than if you paid off the mortgage in 15, then started investing. But yeah, doesn’t work as nicely at 6%.
>but if you had a 3% mortgage, you would have better returns taking the 30 year and investing the difference each month
That would have been a good strategy over last decade certainly. Though that's hindsight and you're effectively taking out a loan and investing the money.
Obviously it you can't control yourself with money then don't do this.
When I bought my house I went with the 30 year mortgage. The interest rates between 15 years and 30 years were not hugely different and my 30 year interest rate was so low. I ended up really glad I did.
If the rates between the 10/15/20/30 are roughly the same, then the person should take the 30 and pay it back like they would the 15 (~double payments). The reason is the person is now protecting themselves from life change risk. If they lose their job they could go back to making the minimum payment.
The advantages of getting the 30 yr are
a) You don't have to keep paying that extra principle on your 30 year mortgage. If you lose your job or whatever, you can fall back to making the regular payments
b) The time value of money aspect. My mortgage is currently well below inflation. $151894 in 2035 dollars might be more expensive than $215838 in 2060 dollars. Especially if you're able to reap the tax benefits of mortgage interest.