Compound Interest Calculator — See How Your Money Grows
Set your principal, rate, time, compounding frequency, and any monthly deposits. Your maturity value, total interest, and a year-by-year breakdown update live — in your browser, with nothing stored.
Compound Interest Calculator
Visualize the power of compounding
₹
₹1K₹1Cr
%
1%30%
Yr
1 Yr40 Yr
₹
₹0₹1L
Total Value₹3,10,585
Total Invested₹1,00,000
Interest Earned₹2,10,585
Growth Over Time
InterestInvested
210%
Returns
Investment Breakdown
Total Invested₹1,00,000
32%
Interest Earned₹2,10,585
68%
Year-by-Year Breakdown
Year
Opening
Interest
Closing
How to Use the Compound Interest Calculator
Set your Principal Amount — the money you start with.
Choose the Annual Interest Rate.
Select a Compounding Frequency — annual, semi-annual, quarterly, or monthly.
Pick the Time Period, and optionally add a recurring Monthly Contribution.
Results — total value, interest earned, the invested-vs-interest breakdown, and a year-by-year table — update instantly as you move the sliders.
The Compound Interest Formula
A = P × (1 + r/n)nt
P = principal • r = annual rate (decimal) • n = times compounded per year • t = years
Example — ₹1,00,000 at 10% for 10 years, compounded annually: A = 1,00,000 × (1.10)10 ≈ ₹2,59,374, meaning ₹1,59,374 interest on ₹1,00,000 invested.
Simple vs Compound Interest — The Difference in Numbers
₹1,00,000 at 10% for 10 years:
Type
Interest earned
Final value
Simple interest
₹1,00,000
₹2,00,000
Compound interest (annual)
₹1,59,374
₹2,59,374
Same principal, rate, and time — but compounding earns ₹59,374 more. Over longer periods the gap widens dramatically.
How Compounding Frequency Affects Your Returns
₹1,00,000 at 10% for 10 years:
Compounding
Final value
Annually
₹2,59,374
Semi-annually
₹2,65,330
Quarterly
₹2,68,506
Monthly
₹2,70,689
The more often interest is added, the more you earn. Switching from annual to monthly here adds about ₹11,000 — same money, just compounded more often. Try the Compounding Frequency buttons above.
How Long to Double Your Money? (Rule of 72)
The Rule of 72 is a quick shortcut: divide 72 by your annual return to estimate the years it takes your money to double.
Annual return
Years to double (72 ÷ rate)
6%
~12 years
8%
~9 years
10%
~7.2 years
12%
~6 years
It’s an approximation (most accurate around 6–10%), but a fast way to compare investments and see why a higher rate — or more time — matters so much.
The Power of Starting Early
Because compounding accelerates over time, the years you don’t invest are the most expensive. ₹1,00,000 compounding at 10% annually becomes about ₹2.59 lakh after 10 years, ₹6.73 lakh after 20 years, and ₹17.45 lakh after 30 years. Most of that growth happens in the later years — which is why starting a decade earlier often matters more than investing a larger amount later.
Frequently Asked Questions
Use A = P × (1 + r/n)nt, where P is the principal, r the annual rate, n the times it compounds per year, and t the years. Instead of doing it by hand, enter your values above and the maturity value, interest earned, and a year-by-year breakdown appear instantly.
Using A = P(1 + r)t: 8,000 × (1.05)² = ₹8,820. The compound interest is ₹820. Confirm it by entering ₹8,000, 5%, 2 years, and annual compounding above.
Simple interest is calculated only on the original principal; compound interest is calculated on the principal plus previously earned interest, so it grows faster. On ₹1,00,000 at 10% for 10 years, simple interest earns ₹1,00,000 while annual compound interest earns ₹1,59,374 — about ₹59,374 more.
Yes, slightly. On ₹1,00,000 at 10% for 10 years, annual compounding gives about ₹2,59,374 while monthly compounding gives about ₹2,70,689 — roughly ₹11,000 more, because interest is added more often.
Use the Rule of 72 — divide 72 by your annual return. At 6% your money doubles in about 12 years, at 10% in about 7.2 years, and at 12% in about 6 years. It’s an approximation, most accurate for rates between 6% and 10%.
The “7-3-2 rule” is an informal mnemonic that’s defined loosely and inconsistently across sources, so treat it as a rough memory aid rather than a precise formula. For an accurate estimate of doubling time, use the Rule of 72: divide 72 by your annual return (for example, 72 ÷ 10 ≈ 7.2 years to double at 10%).
Yes. Use the Monthly Contribution input to add a recurring deposit. The calculator compounds both your starting principal and each monthly addition — useful for planning SIPs, recurring deposits, or regular savings.
Yes. It runs entirely in your browser, requires no sign-up, and does not collect or store any data. It uses standard financial formulas and gives estimates based on the values you enter.
