Compound Interest Calculator
Calculate compound interest growth on savings, retirement funds, and investments over time.
Visualize the power of compound interest. Calculate future investment value, total interest accrued, and principal contributions across daily, monthly, or annual compounding intervals.
About Compound Interest Calculator
Albert Einstein famously called compound interest the eighth wonder of the world. Compound Interest Calculator allows investors and savers to forecast wealth accumulation, evaluate 401(k) and IRA projections, and understand how time amplifies investment growth.
How to Use Compound Interest Calculator
- Enter initial investment: Type the starting principal balance.
- Set interest rate & term: Enter the annual interest rate (APY/APR) and duration in years.
- Add regular contributions: Optionally specify monthly or annual deposit amounts.
- Analyze compounding results: Review your total future balance, accrued interest, and growth timeline.
Key Features
- Daily, monthly, quarterly, annual compounding
- Initial deposit plus ongoing monthly contributions
- Calculates total interest earned vs principal invested
- Visual growth breakdown
- 100% client-side
Common Use Cases
- Projecting retirement nest egg growth in 401(k) and Roth IRA accounts.
- Estimating returns from high-yield savings accounts and certificates of deposit (CDs).
- Comparing stock market index fund dollar-cost averaging scenarios.
Formula & Calculation Logic
Compound Interest Formula: A = P(1 + r/n)^(nt). Total Interest = A - P - (Monthly Contribution × 12 × t).
Frequently Asked Questions
What is the compound interest formula?
A = P(1 + r/n)^(nt), where P is principal, r is annual interest rate (in decimal), n is compounding frequency per year, and t is time in years.
What is the difference between simple and compound interest?
Simple interest only earns return on the initial principal. Compound interest earns interest on both principal and previously accumulated interest, accelerating growth exponentially.
How does compounding frequency impact returns?
More frequent compounding (e.g., daily or monthly vs annually) generates slightly higher total yield because interest starts earning interest sooner.
Is this calculator accurate for high-yield savings and index funds?
Yes! It accurately projects fixed savings yields and expected average stock market returns (e.g. S&P 500 historical average of 7-10%).
Privacy Guarantee
Financial calculations run 100% locally in your browser. No financial data is transmitted or stored.
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