Compound Interest Calculator

Free compound interest calculator. See how your money grows with interest on interest — total amount, interest earned and a year-by-year breakdown for any frequency.

✓ Free ⚡ Instant 🔒 100% private
Details
Principal amount
₹1K₹1 Cr
Annual interest rate%
1%25%
Time periodyears
1 yr40 yrs
Compounding frequency
Result
Total amount₹0
Principal
₹0
Compound interest
₹0
Year-by-year growth
YearOpeningInterestClosing balance

🔒 Calculated entirely in your browser — nothing is uploaded.

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Free Compound Interest Calculator

This free online compound interest calculator shows how much your money grows when interest earns interest. Enter a principal, an annual interest rate, a time period and how often interest compounds, and instantly see the total amount, the interest earned and a year-by-year breakdown. It’s free and runs entirely in your browser.

How to use the compound interest calculator

  1. Enter the principal — the starting amount.
  2. Set the annual interest rate.
  3. Choose the time period in years.
  4. Pick how often interest compounds (yearly, half-yearly, quarterly, monthly or daily).
  5. See the total amount, interest earned and the year-by-year growth table.

What is compound interest?

Compound interest is interest calculated on both your original principal and the interest already added. The formula is A = P × (1 + r/n)n×t, where P is the principal, r is the annual rate (as a decimal), n is how many times it compounds per year and t is the number of years. The interest earned is simply A − P.

The magic of compounding is that growth accelerates over time — the longer you leave money invested, the bigger the difference compared with simple interest. More frequent compounding and a higher rate both increase the final amount, but time is usually the most powerful factor, which is why it’s often called the eighth wonder of the world.

Frequently asked questions

Is this compound interest calculator free and private?
Yes. It’s completely free with no sign-up, and the calculation runs entirely in your browser. Nothing you enter is uploaded to a server.
What is the difference between simple and compound interest?
Simple interest is calculated only on the original principal. Compound interest is calculated on the principal plus all previously added interest, so it grows faster over time.
Does compounding frequency matter?
Yes. The more often interest is compounded, the more often it starts earning interest itself. Daily compounding gives a slightly higher result than yearly compounding at the same rate, though the difference is small.
How is compound interest calculated?
Using A = P × (1 + r/n)^(n×t). The tool computes the total amount A and subtracts the principal to show the interest earned, and lists the balance at the end of each year.
Why does time matter so much?
Because each year’s interest is added to the base that earns interest next year, growth accelerates. The final years contribute far more than the early ones, so a longer time horizon dramatically increases the total.
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