Compound Interest Calculator: Growth Simulator
Simulate long-term investment growth with compound interest. Calculate deposits, interest rate and total returns.
Projected Future Balance
$112,900.64
Total Invested
$65,000.00
Total Interest Earned
$47,900.64
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This simulator projects compound wealth accumulation by calculating interest compounded periodically on principal plus recurring monthly deposits.
Calculation Formula
A = P(1 + r/n)^(nt) + PMT × [((1 + r/n)^(nt) - 1) / (r/n)], where A is future balance, P is principal, r is annual rate, n is compounding frequency, t is years, and PMT is monthly deposit.
Practical Example
Investing $10,000 initially plus $500 monthly at an 8% annual return over 20 years results in $130,000 deposited and over $190,000 in compound interest, reaching a final nest egg of ~$320,000.
Frequently Asked Questions (FAQ)
What is the rule of 72 in compound interest? ▼
The Rule of 72 is a quick mental math shortcut: divide 72 by your annual interest rate to find the approximate number of years it takes for your investment to double.
How often does compounding occur in this calculator? ▼
Contributions and compounding are calculated on a monthly compounding frequency, which matches typical savings and brokerage account cycles.
What is the difference between APR and APY? ▼
APR (Annual Percentage Rate) does not account for intra-year compounding, while APY (Annual Percentage Yield) reflects the true annual return taking compounding into effect.
Can I download the results of this simulation? ▼
Yes, click the "Print / Download PDF" button to export a complete branded financial summary table formatted for sharing or archiving.