Since I couldn't easily get my unpaid principal balance, I calculated my mortgage balance using a handful of online calculators. Today I took a look at the actual balance, and was rather surprised to see it's off by $1,000 from what online calculators showed.
Before I go yell at my bank, I'd like to know if there's a surefire way to know the proper balance. Aside from the original balance, the interest rate, what I've been paying, and how long I've been paying it, is there any other information I need to accurately calculate my mortgage? Is there a reliable way I can calculate my balance without relying on questionable online calculators?