I have a couple of Excel Calculators that I use frequently. Below is a list with links for easy access:
Compound vs. Simple Interest Calculator: This calculator compares simple and compound interest over forty years. It has a graph that updates based on inputs, which are PV (present value) and the interest rate.
Mortgage Calculator: This calculator provides a detailed amortization schedule based off user defined values. Values are loan amount, interest rate, loan term, payments per year, and loan repayment start state. You can add extra payments to show how your mortgage will adjust.
I’ll add more as I come across them.