Small, consistent contributions can grow into a surprisingly large sum over time thanks to USA compound interest — the effect of earning returns not just on your original investment, but on all the interest that’s already accumulated. This calculator shows exactly how your savings or investment could grow over any number of years based on your contribution amount and expected rate of return.
USA Compound Interest Calculator
See how your initial savings and regular contributions grow over time with the power of compounding.
Total Portfolio Breakdown
Annual Growth Summary
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The earlier you start, the more time compounding has to work in your favor, which is why even modest amounts invested in your 20s can outgrow larger amounts invested later in life. For the full explanation of why this matters so much for long-term wealth building, read our guide on how compound interest works, and if you’re specifically planning for retirement, our 401k calculator and SIP calculator apply the same principle to different account types.
Enter your starting amount, contribution rate, and time horizon above to see your projected growth over time.