Compound Interest Calculator
Calculate how interest compounds over time with different frequencies. See APY, ...Calculate how interest compounds over time with different frequencies. See APY, year-by-year growth tables, and understand the power of compounding. S...
Updated
Can be $0 for contribution-only plans
Can be 0% for simple savings tracking
Recurring deposit (SIP, RD, or 401k style) added at period end
A $10,000.00 investment at 5% compounded monthly grows to $16,470.09 in 10 years, earning $6,470.09 in interest.
Final Balance
$16,470.09
Total Interest Earned
$6,470.09
Total Invested
$10,000.00
Investment Breakdown
APY (Effective Rate)
5.12%
Doubling Time
~14.4 years
Year-by-Year Growth
Final: $16,470.09| Year | Start Balance | Deposits | Interest | End Balance |
|---|---|---|---|---|
| 1 | $10,000.00 | - | +$511.62 | $10,511.62 |
| 2 | $10,511.62 | - | +$537.79 | $11,049.41 |
| 3 | $11,049.41 | - | +$565.31 | $11,614.72 |
| 4 | $11,614.72 | - | +$594.23 | $12,208.95 |
| 5 | $12,208.95 | - | +$624.63 | $12,833.59 |
| 6 | $12,833.59 | - | +$656.59 | $13,490.18 |
| 7 | $13,490.18 | - | +$690.18 | $14,180.36 |
| 8 | $14,180.36 | - | +$725.49 | $14,905.85 |
| 9 | $14,905.85 | - | +$762.61 | $15,668.47 |
| 10 | $15,668.47 | - | +$801.63 | $16,470.09 |
| Total | - | - | $6,470.09 | $16,470.09 |
Compound Interest Formula
Principal Only
With Regular Contributions (PMT)
A = Final amount (future value)
P = Principal (initial investment)
r = Annual interest rate (decimal)
n = Compounding frequency per year
t = Time in years
PMT = Regular contribution amount
i = Rate per contribution period
N = Total number of contributions
Calculation Method
This calculator uses month-by-month simulation for exact accuracy. Regular contributions are added at the end of each period (ordinary annuity). Interest compounds at your selected frequency, so the year-by-year table always matches the summary totals.
Quick answer
Compound interest is interest calculated on both your initial principal and the interest already earned, so your money grows faster over time. This free calculator applies the formula A = P(1 + r/n)^(nt), where P is your principal, r is the annual rate, n is the number of times interest compounds per year, and t is the number of years. It shows your final balance, total interest earned, APY, and a year-by-year growth table, and it also handles regular monthly or annual contributions in USD, INR, EUR, or GBP.
Calculator Features
Why Use Compound Interest Calculator?
5 Compounding Frequencies
Compare daily, monthly, quarterly, semi-annual, and annual compounding to see how frequency affects your returns.
Year-by-Year Growth Table
Detailed breakdown showing start balance, deposits, interest earned, and end balance for each year.
APY Display
See your effective annual percentage yield (APY) - the true return after compounding is factored in.
Rule of 72 Calculation
Instantly see how long it takes to double your money at your chosen interest rate.
SIP / Monthly Contributions
Include systematic investment plan (SIP) contributions to see how regular deposits accelerate growth.
Visual Breakdown
Interactive chart showing principal, contributions, and interest earned as percentages of final value.
Perfect For
High-Yield Savings Accounts
Calculate actual returns on HYSA with daily compounding. Compare APY offers from different banks.
Certificate of Deposits (CDs)
Project CD returns with different terms and compounding frequencies. Plan CD laddering strategies.
Fixed Deposits (FD)
Calculate maturity value of fixed deposits with quarterly or annual compounding.
SIP / Recurring Deposits
Plan systematic investment with monthly contributions. See how regular deposits compound over time.
How It Works
Enter Principal Amount
Input your starting balance. This can be $0 if you're calculating SIP-only growth.
Set Interest Rate & Period
Enter the annual interest rate (APR) and number of years. Rates can be 0% for simple savings tracking.
Choose Compounding Frequency
Select how often interest compounds: daily (365x), monthly (12x), quarterly (4x), semi-annually (2x), or annually (1x).
Add Monthly Contributions
Optionally enter regular monthly contributions (SIP). Watch how small, consistent deposits compound dramatically.
Interest Tips
Compare APY, Not APR
When comparing savings accounts or CDs, always compare APY (not APR). APY already factors in compounding frequency, giving you the true annual return.
Monthly Contributions Matter Most
Over long periods, regular monthly contributions often contribute more to final balance than the initial principal. Consistency beats trying to time the market.
Compounding Frequency Difference is Small
Daily vs. annual compounding at 6% APR only adds ~0.17% to APY. Don't choose an account solely for compounding frequency - interest rate matters more.