About Iota-Home

I built Iota-Home because the mortgage calculators I found online didn’t answer the questions I had.

Most of them take a loan amount, a rate, and a term, and give you a monthly payment. That’s useful for about five minutes. After that you start asking harder questions. Should you put extra money toward principal or keep it? When does PMI go away? What does an ARM look like if rates move against you? Does refinancing make sense when you count the closing costs? To get those answers I ended up building my own spreadsheet.

Iota-Home is that spreadsheet turned into a website. You enter your actual loan, and it shows you the full payment schedule. You can change one thing at a time and see the effect. It’s free, and you don’t need to know Excel.

About me

I’m Charles Kulas. I work in pricing strategy, which mostly means building models to test whether a decision is worth making before anyone commits to it. Iota-Home applies the same approach to a mortgage. It doesn’t recommend anything. It shows you what each option costs so you can decide.

How the numbers are calculated

Every rule the calculators follow, from PMI timing to ARM adjustments, is written out on the methodology page.