Some people think that paying home equity based interest is a good idea since they get to write it off on their taxes. This thinking leads them to believe they can use a HELOC like a credit card and let their balance grow as they pay more interest which eventually drowns them in further debt. This calculator shows you what happens. Included are buttons to set your monthly payment to be either an interest-only value or enough to pay off the loan in 10 or 30 years.