Conscious Finance
Compound Interest Calculator
Enter your investment details to see exactly how your money grows over time — your final balance, total interest earned, and a year-by-year breakdown of the compounding effect.
The Compound Interest Formula
For a lump sum with no contributions: A = P(1 + r/n)^(nt), where P is the principal, r is the annual interest rate as a decimal, n is the number of times interest compounds per year, and t is the number of years.
When regular contributions are added, the future value of those contributions is calculated separately using the annuity formula and added to the compounded principal. This calculator handles both simultaneously, giving you an accurate picture of how your contributions and your initial investment combine to produce your final balance.