Calculators
Compound Interest Calculator
Calculate how your potential investment grows over time with compound interest. Supports monthly contributions, different compounding frequencies, and inflation adjustment.
Use Compound Interest Calculator to get instant results without uploads or sign-ups. Everything runs securely in your browser for fast, reliable output.
Your results will appear here.
About this tool
Albert Einstein reputedly called compound interest the "eighth wonder of the world". It is the principle where the interest you earn also earns interest, causing your wealth to grow exponentially rather than linearly.
Our Compound Interest Calculator helps you visualize this growth. Unlike simple interest calculators, this tool allows you to factor in regular monthly deposits and see the difference between compounding daily, monthly, or annually.
Use this tool to plan for retirement, a down payment on a house, or to see how much your savings account will really be worth in 10 years.
Usage examples
Basic Savings
$10k start, 5% for 10 years
Start: $10,000, Rate: 5%, Years: 10 → Future Value: $16,470
Regular Investing
$100/mo extra
Start: $0, Add: $500/mo, Rate: 7%, Years: 30 → Future Value: $588,000+
How to use
- Enter your "Initial Investment" amount.
- Enter your "Monthly Contribution" (optional).
- Set the "Interest Rate" (APUY) you expect to earn.
- Choose format (Years to grow) and Compounding Frequency.
- Click "Calculate" to see your future balance.
Benefits
- Visualize exponential growth
- Supports regular monthly additions
- Adjustable compounding frequency (Daily to Annually)
- Inflation adjustment option
- Breakdown of Principal vs Interest earned
- Instant results
- Works offline
FAQs
What is Compound Interest?
Compound interest is interest calculated on the initial principal, which also includes all of the accumulated interest from previous periods using a set rate.
Which compounding frequency is best?
The more frequently interest compounds (e.g., Daily vs Annually), the more money you make. Daily compounding is mathematically the best for the saver.
How much can I save in 10 years?
It depends on your initial investment, monthly contributions, and interest rate. For example, $5,000 initial + $100/month at 7% compounded monthly grows to over $22,000 in 10 years.
What is the rule of 72?
Divide 72 by your interest rate to estimate how many years it takes to double your money. At 6% interest, your money doubles in about 12 years (72÷6=12).
Is compound interest better for long-term investments?
Yes! Compound interest becomes dramatically more powerful over longer time periods. The exponential growth effect means that years 20-30 of investing produce far more wealth than years 1-10. Starting early is crucial for maximizing compound growth.
Should I make monthly contributions or invest a lump sum?
Both are beneficial. Monthly contributions (dollar-cost averaging) reduce timing risk and make investing accessible. A large lump sum starts compounding immediately. Ideally, invest lump sums when available AND maintain regular monthly contributions for best results.
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