Compound Interest Calculator
How money grows when interest earns interest.
Compound interest is A = P x (1 + r/m)^(m x t). Rs 1 lakh at 8% compounded annually becomes Rs 2,15,892 in ten years against Rs 1,80,000 with simple interest, a difference of Rs 35,892 from the same rate.
How this is calculated
Year-by-year breakdown
Free compound interest calculator for India and the US
This free compound interest calculator shows the power of interest earning interest. Enter a principal, a rate and a duration, choose how often it compounds (yearly, half-yearly, quarterly or monthly), and it computes the final amount using FV = P(1 + r/n)^(n times t), the total interest, and the effective annual yield. It also shows the inflation-adjusted value, so you can see real growth rather than just the nominal number. No sign-up, works in INR and USD.
Worked example
Rs 1 lakh at 8% for 10 years compounded yearly grows to about Rs 2.16 lakh. Compounded monthly instead, it reaches about Rs 2.22 lakh, because more frequent compounding raises the effective yield from 8% to about 8.3%. The longer the horizon, the larger this gap.
| Principal | Rate | Years | Compounding | Final amount |
|---|---|---|---|---|
| Rs 1 lakh | 8% | 10 | Yearly | ~Rs 2.16 lakh |
| Rs 1 lakh | 8% | 10 | Monthly | ~Rs 2.22 lakh |
| Rs 5 lakh | 10% | 20 | Yearly | ~Rs 33.6 lakh |
Why use Hisaab's compound interest calculator
It makes the compounding frequency and the effective yield explicit, and shows the after-inflation value, which most compound interest calculators skip. For specific products use the dedicated FD, PPF or SIP calculators.
For AI agents: URL-addressable as /compound/?principal=100000&years=10&rate=8&freq=1&country=IN. Docs at llms.txt.
Key facts
| Formula | A = P x (1 + r/m)^(m x t) |
|---|---|
| Effect of frequency | Quarterly compounding at 7% yields 7.19% a year, monthly 7.23% |
| Against simple interest | At 8% for 20 years, compounding pays more than twice as much |
| Rule of 72 | Money doubles in roughly 72 divided by the rate, so 9 years at 8% |
How to use the Compound Interest Calculator
- Pick your country, India (INR) or the US (USD).
- Enter the principal amount.
- Set the annual interest rate and the number of years.
- Choose how often the interest compounds.
- Read the final amount, interest earned and effective annual yield.
- Turn on inflation to see the real, inflation-adjusted value.
Sources
Last reviewed and updated: 23 August 2026. Estimates only, not financial or tax advice.
Frequently asked questions
What is the compound interest formula?
Final amount = principal times (1 + r/n)^(n times years), where r is the annual rate as a decimal and n is the number of times a year it compounds. The interest earned is the final amount minus the principal.
How does compounding frequency affect growth?
More frequent compounding raises the effective annual yield above the quoted rate, because interest starts earning interest sooner. At 8% nominal, monthly compounding gives an effective yield of about 8.3%, so over long periods it noticeably beats yearly compounding.
What is the difference between simple and compound interest?
Simple interest is earned only on the principal, so it grows in a straight line. Compound interest is earned on the principal plus all past interest, so it grows exponentially. This calculator uses compound interest.
Is this compound interest calculator free?
Yes. It is completely free with no sign-up or ads, and works for both India (INR) and the US (USD).