Wealth Accumulation Engine

Compound Interest Calculator

Project your future investment growth, interest earned, and maturity balance with custom compounding intervals.

₹
Starting lump-sum investment
%
Expected annual rate of return
Yrs
Rule of 72: Doubles in ~7.2 years
How often returns are reinvested
Add Regular Monthly Contribution (SIP Deposit)
₹
Leave 0 for lump-sum only
When deposit accrues interest
Total Maturity Future Value
₹82,265.40 1.65x Return

Investing ₹50,000 at 10% for 5 years compounded monthly

Initial Principal ₹50,000.00 Initial lump sum
Regular Deposits ₹0.00 Monthly add-ons
Total Interest ₹32,265.40 +64.5% profit
Effective APY 10.47% Annualized yield
Principal Capital: 60.8% Compounded Interest: 39.2%
View Year-by-Year Growth Table
Year Deposited Capital Interest Accrued Maturity Balance

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About the Compound Interest Calculator

Compound interest is the fundamental engine behind long-term wealth creation. Unlike simple interest—which produces fixed, linear returns calculated exclusively on the original deposit—compounding reinvests every dollar of earned interest so that future cycles earn interest on top of past interest.

1. The Core Compounding Formula

A = P(1 + r/n)nt

  • A: Final maturity balance
  • P: Initial principal investment
  • r: Annual nominal interest rate (decimal)
  • n: Compounding intervals per year
  • t: Investment duration in years

2. Effective Annual Yield (APY)

APY = (1 + r/n)n - 1

Measures true annualized percentage yield. For instance, a 10% rate compounded monthly yields an effective annual return of 10.47%.

Compounding Frequency Comparison on $10,000 at 8% for 10 Years

Compounding Interval Cycles / Year ($n$) Effective APY Final Maturity Balance
Annually 1 8.00% $21,589.25
Semi-Annually 2 8.16% $21,911.23
Quarterly 4 8.24% $22,080.40
Monthly 12 8.30% $22,196.40
Daily 365 8.33% $22,253.46

Frequently Asked Questions

What is compound interest and how is it different from simple interest?

Simple interest is calculated exclusively on your original principal deposit throughout the entire life of the investment. Compound interest adds each cycle's accrued interest back into the principal baseline, meaning future earnings grow exponentially rather than linearly. Over long investment periods, compounding generates the vast majority of total wealth.

How does compounding frequency impact returns?

The higher the compounding frequency, the greater the final maturity sum. When returns are credited monthly or daily rather than annually, earned interest begins multiplying sooner. For example, $10,000 at 10% compounded annually yields $25,937 in 10 years, whereas monthly compounding yields $27,070 (an extra $1,133 with identical risk).

What is the Rule of 72 and how do I use it?

The Rule of 72 is a mental math heuristic used to approximate the number of years needed to double your initial capital. Simply divide 72 by the annual expected interest rate. At 8% annual return, your money doubles in approximately 9 years ($72 \div 8 = 9$). At 12% annual return, it doubles in roughly 6 years ($72 \div 12 = 6$).

Can I calculate monthly Systematic Investment Plans (SIP) with this tool?

Yes. Expand the "Add Regular Monthly Contribution" option above to factor in recurring monthly deposits. The tool factors both your initial lump-sum principal and recurring annuity cash flows according to standard Future Value of Annuity equations.

Is my financial calculation data stored or shared?

Never. All financial calculations occur 100% locally in your web browser via client-side JavaScript. None of your portfolio amounts, returns, or time horizons are sent across the network or stored in databases.