Compound Interest Calculator – Investment & Savings Growth
The power of compound interest
Compound interest is interest calculated on the initial principal as well as the accumulated interest from previous periods. Over long time horizons (10 to 30 years), regular monthly contributions combined with reinvested compounding returns typically grow exponentially, often exceeding the total out-of-pocket contributions by multiples.
Rule of 72
To approximate how many years it will take to double your money with compounding, divide 72 by your expected annual interest rate. For example, an 8% annual return doubles your money in roughly 9 years (72 ÷ 8 = 9).
Frequently asked questions
How often is interest compounded in this tool?
Interest is compounded monthly to align with monthly deposits.
Does this account for inflation or capital gains taxes?
No, these projections represent nominal returns. Real purchasing power depends on prevailing inflation rates and applicable investment taxes.