Mortgage interest rates have recently risen, and are currently very volatile. At the time of this writing, PSECU, my credit union, is offering mortgages at 5.125%, much higher than the 3.125% I locked in at, but lower than the peak above 6% I had recently read about in the news. But what does this mean in practice? Well, let’s run some numbers.

Understanding how expensive a house is can be confusing. The total price of a house is a huge number, more money than we normally ever deal with, for most first-time buyers more money than they’ve ever actually had or seen. It can be intimidating.

I just bought a house, and it came with a mortgage. I bought the house and committed to the mortgage all in one ceremony, in a cute little office where I signed enough papers that the sellers were able to solemnly hand me the keys to my new castle. In the lead-up to this, I was told how early payments, mortgage insurance, and refinancing works, and it’s – I think very reasonably – been on my mind since.