Compound Interest Calculator
Calculate compound interest, maturity amount, investment growth, and total interest earned instantly using annual, monthly, quarterly, or daily compounding.
Compounding reinvests accrued interest back into the principal baseline, creating exponential wealth growth over time. Using the classical Rule of 72 (dividing 72 by the annual interest rate), an investment at 12% compounding doubles every 6 years, whereas simple interest only grows linearly.
Compounding Frequencies & The Rule of 72
Rule of 72 Doubling Time MetricOn a ₹10 Lakh principal at 10% p.a. over 10 years, annual compounding yields ₹25.93 Lakhs, while daily compounding yields ₹27.18 Lakhs (+₹1.25 Lakhs extra due solely to compounding velocity).
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How the Compound Interest Calculator Works
Follow these simple steps to get accurate results instantly.
Enter Principal Amount
Enter the initial amount invested or deposited.
Enter Interest Rate
Provide the annual interest rate percentage.
Enter Time Period
Enter the investment duration in years.
View Results
Get maturity amount, compound interest, and investment growth instantly.
Compound Interest Formula
A = P(1 + r/n)^(nt)
Compound interest is calculated on both the principal amount and the accumulated interest from previous periods. It allows investments to grow faster compared to simple interest.
Example Calculation
Input: Principal: ₹10,000, Rate: 10%, Time: 2 Years
Output: A = 10000(1 + 0.10/1)^(1×2) = ₹12,100
Common Uses
- • Investment Planning
- • Fixed Deposits
- • Mutual Funds
- • Savings Accounts
- • Retirement Planning
- • Wealth Growth Analysis
Frequently Asked Questions
Verified answers to essential calculation and diagnostic questions.
Compound interest is interest earned on both the principal amount and previously accumulated interest.
A = P(1 + r/n)^(nt), where P is principal, r is annual interest rate, n is compounding frequency, and t is time in years.
Compound interest helps investments grow faster because earnings are continuously reinvested.
Simple interest is calculated only on principal, while compound interest is calculated on principal plus accumulated interest.
Yes. This calculator can be used for fixed deposits, savings accounts, investments, and retirement planning.
What is Compound Interest?
Compound interest is the interest earned not only on your original investment but also on previously earned interest. This creates a snowball effect that helps your money grow faster over time.
Simple Interest vs Compound Interest
| Feature | Simple Interest | Compound Interest |
|---|---|---|
| Interest Calculation | Principal Only | Principal + Earned Interest |
| Growth Rate | Linear | Exponential |
| Long-Term Wealth | Lower | Higher |
The Power of Compounding
Albert Einstein is often credited with calling compound interest the eighth wonder of the world. The longer your money remains invested, the more powerful compounding becomes.
Investment Growth Example
| Investment | Rate | Time | Approx. Value |
|---|---|---|---|
| ₹1,00,000 | 10% | 10 Years | ₹2,59,374 |
| ₹1,00,000 | 10% | 20 Years | ₹6,72,750 |
| ₹1,00,000 | 10% | 30 Years | ₹17,44,940 |
Factors Affecting Compound Interest
- Principal Amount: Larger investments generate larger returns.
- Interest Rate: Higher rates accelerate growth.
- Time Period: More years means greater compounding.
- Compounding Frequency: Monthly compounding generally earns more than annual compounding.
Compounding Frequency Comparison
| Frequency | Description |
|---|---|
| Annually | Interest added once per year. |
| Semi-Annually | Interest added twice per year. |
| Quarterly | Interest added four times per year. |
| Monthly | Interest added twelve times per year. |
How to Maximize Compound Growth
- Start investing as early as possible.
- Invest consistently every month.
- Reinvest returns instead of withdrawing them.
- Stay invested during market fluctuations.
- Increase investments when income rises.
Common Compounding Mistakes
- Starting investments too late.
- Withdrawing money frequently.
- Ignoring inflation.
- Expecting quick results.
- Stopping investments during market downturns.
Rule of 72
The Rule of 72 estimates how long it takes for an investment to double. Simply divide 72 by the annual interest rate. For example, at 8% returns, money doubles in approximately 9 years.
Pro Tip
The biggest advantage in investing is time. Starting a ₹5,000 monthly investment at age 25 instead of age 35 can potentially result in several times more wealth by retirement due to compound growth.
Written & maintained by Aditya Singh
Aditya Singh is a software engineer and the founder of DevCalc, based in Uttar Pradesh, India. He builds and maintains every calculator on this site, using standard, verified formulas — the same ones used by banks, institutions, and educators — with careful attention to accuracy. Read more about the author →
This calculator and its guidance are for general educational purposes only and do not constitute financial, investment, or tax advice. Verify figures with a qualified professional before making financial decisions.