Understanding the Compound Interest Formula
The compound interest formula A = P(1 + r/n)^(nt) has four variables: P = principal (initial amount), r = annual interest rate (decimal), n = number of times interest compounds per year, and t = time in years. A is the final amount. For example, $5,000 at 6% compounded quarterly for 10 years: A = 5000(1 + 0.06/4)^(4×10) = 5000(1.015)^40 = 5000 × 1.8140 = $9,070.09.