Compound Interest Calculator
Use this compound interest calculator to find the future value and interest earned with daily, monthly, quarterly, semi-annual or annual compounding.
Starting investment amount
Nominal annual interest rate
Duration of compounding
How often interest is compounded onto principal
Compounding Rule
Results
For information only. Not financial advice. Results are estimates.
A compound interest calculator estimates how one deposit grows when earned interest stays invested. Enter the starting amount, annual rate, time and compounding frequency to see the future balance and interest earned. The estimate assumes the same rate throughout and excludes tax, fees and inflation.
Compound interest formula
For a single deposit, the compound interest formula is:
A = P × (1 + r / n)n × t
- P: initial deposit; A: final balance.
- r: nominal annual rate as a decimal, so 8% is 0.08.
- n: periods per year; t: years invested.
- Interest earned = A − P.
The daily compound interest formula uses n = 365; monthly uses 12, quarterly 4, semi-annual 2 and annual 1. These are this calculator’s conventions. Check the product’s accrual rules before comparing a bank statement with the estimate.
An effective annual rate is (1 + r/n)n − 1. For the example’s 8% nominal rate, monthly compounding gives 8.30% over one year. Investor.gov explains why interest on accumulated interest grows the balance.
Worked example: one deposit over ten years
Assume a ₹1,00,000.00 deposit earns 8% a year, compounded annually, for 10 years. The rate is an illustration, not a current savings or investment offer.
1. Annual compounding means one interest credit per year.
2. The growth factor is (1 + 8 / 100)10 = 2.158925.
3. Multiply the deposit by that factor: the final balance is ₹2,15,892.50.
4. Subtract the original deposit: interest earned is ₹1,15,892.50, a total return of 115.89%.
Daily, monthly, quarterly or annual compounding?
| Frequency | Final balance | Interest earned |
|---|---|---|
| annually | ₹2,15,892.50 | ₹1,15,892.50 |
| quarterly | ₹2,20,803.97 | ₹1,20,803.97 |
| monthly | ₹2,21,964.02 | ₹1,21,964.02 |
| daily | ₹2,22,534.58 | ₹1,22,534.58 |
Monthly compounding adds ₹6,071.52 to the final balance compared with annual compounding under these assumptions. More frequent compounding has no benefit if interest is withdrawn instead of reinvested.
Compound interest with monthly contributions
A monthly contribution earns for fewer periods when it is deposited later. This page’s one-deposit formula cannot model that by adding all future deposits to the principal.
Use the SIP calculator for monthly investments to model regular contributions, or the savings goal calculator to work out the monthly amount needed after allowing for existing savings. Investor.gov’s calculator has separate inputs for an initial investment and monthly contributions.
What the result assumes
The example keeps the rate constant, reinvests every interest credit and makes no further deposits or withdrawals. It excludes taxes, charges and changes in purchasing power. Market-linked returns vary, so a smooth projection does not predict the path of an investment.
For rate terminology, read APR vs APY and compounding frequency. To compare a non-compounding calculation, use the simple interest calculator.
Frequently asked questions
What is compound interest?
How do you calculate compound interest?
Is daily compounding better than monthly compounding?
Can I calculate compound interest with monthly contributions?
How long does compound interest take to double money?
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Future Value
₹2,15,892