Compound Interest Calculator

Compound interest is the process where interest earned is added back to the principal, so you earn interest on interest. It is often called the "eighth wonder of the world" (attributed to Albert Einstein) and is the foundation of long-term wealth creation.

Our free Compound Interest Calculator helps you calculate how much your investment will grow over time with compounding. Whether you are planning a fixed deposit, recurring deposit, or any investment — enter the principal, interest rate, compounding frequency, and time period to get your maturity amount instantly.

Follow these steps to calculate compound interest:

1. Principal (P): Enter the initial investment or deposit amount. E.g., ₹1,00,000.
2. Annual Interest Rate (r): Enter the annual interest rate. E.g., 8% p.a.
3. Compounding Frequency (n): Select how often interest is compounded — Annually, Semi-annually, Quarterly, Monthly, or Daily.
4. Time Period (t): Enter the investment duration in years. E.g., 5 years.
5. Click Calculate: Get the maturity amount, total interest earned, and year-wise growth.

Compound Interest Formula:

A = P × (1 + r/n)^(n×t)

Where: A = Maturity Amount, P = Principal, r = Annual rate (decimal), n = Compounding frequency per year, t = Time in years.

Example: ₹1,00,000 at 8% p.a. compounded quarterly for 5 years:

A = 1,00,000 × (1 + 0.08/4)^(4×5) = 1,00,000 × (1.02)^20 = ₹1,48,595

Total Interest Earned = ₹48,595

The difference between compound and simple interest grows dramatically over time:

• Simple Interest on ₹1 lakh at 8% for 10 years: Interest = ₹80,000 | Total = ₹1,80,000
• Compound Interest on ₹1 lakh at 8% for 10 years (quarterly): Interest = ₹1,21,840 | Total = ₹2,21,840

The extra ₹41,840 is pure compounding benefit — earned without investing a single rupee more. Over 20–30 years, this gap becomes enormous, which is why starting early is the most powerful financial decision you can make.