How to Use This Calculator

1. Enter Principal Amount

   Input the initial lump sum you are investing, like ₹50,000 in a fixed deposit or $5,000 in a savings account.

2. Set Annual Interest Rate

   Enter the expected annual rate of return. For example, 7.5% for a PPF account or 9% for mutual funds.

3. Choose Time Period

   Specify the number of years you plan to keep the investment, such as 15 years for retirement planning.

4. Add Monthly Contributions (Optional)

   If you will add money regularly, like a ₹2,000 monthly SIP, enter that amount to see its impact.

5. Select Compounding Frequency

   Choose how often interest is compounded—monthly, quarterly, or annually—based on your financial product.

6. View Detailed Results

   Click "Calculate Growth" to see the future value, total interest, and growth projection instantly.

Key Features

• Accurate & Instant Results

  Performs precise compound interest calculations in real-time with no server delay.

• Handles Monthly Contributions

  Factor in regular SIPs or savings to project total wealth accumulation accurately.

• Flexible Compounding Periods

  Supports annual, semi-annual, quarterly, monthly, and daily compounding frequencies.

• Free Forever

  This is a completely free financial tool with no sign-up, no limits, and no hidden costs.

• Privacy-Focused

  All calculations happen in your browser. We do not store or see your financial data.

• Print & Share Friendly

  Easily print your results for financial planning or share them with your advisor.

Formula & How It Works

The compound interest formula calculates the future value (A) of an investment:

A = P (1 + r/n)^nt + C × [((1 + r/n)^nt - 1) / (r/n)]

Where:
P = Principal amount (initial investment)
r = Annual interest rate (as a decimal)
n = Number of times interest is compounded per year
t = Time in years
C = Monthly contribution (converted to per-period contribution)

The formula combines the growth of the initial lump sum with the future value of a series of monthly contributions. The total interest earned is the future value minus the total of all contributions made.

Practical Examples

What Is Compound Interest?

Compound interest is the interest calculated on the initial principal and also on the accumulated interest of previous periods. It's often called "interest on interest" and is a powerful force in wealth building. Unlike simple interest, which only earns on the principal, compounding allows your money to grow at an accelerating rate over time.

This effect is why starting investments early, even with small amounts, can lead to significant wealth due to the long time horizon for compounding to work. It's fundamental to retirement planning, education funds, and long-term financial goals.

Frequently Asked Questions

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