Compound Interest Calculator
See how an investment grows over time with compound interest and optional monthly contributions.
How it works
Applies A = P(1 + r/n)^(nt) for a lump sum, or simulates month-by-month growth when you add regular monthly contributions.
How does compounding frequency affect returns?
More frequent compounding (e.g. monthly vs. annually) yields slightly higher returns for the same nominal rate.