Annuities, Calculating Value of Regular Annuity

Annuities are the financial engine behind everything from monthly pension payments to home loan EMIs — a stream of equal cash flows spaced at regular intervals. The core question is simple: if you deposit or receive a fixed sum every month for $n$ years, what is that entire series worth today (present value) or at the end (future value)? The formulas you will meet here are just compact ways to sum a geometric series, turnin …