02/09/2026
Compound Interest Calculator
What is Compound Interest Calculator?
Compound interest is interest calculated on both your original principal and the interest already earned in earlier periods — so growth accelerates over time compared to simple interest.
How to use Compound Interest Calculator
Enter your principal (starting amount), the annual interest rate, the number of years, and how many times per year interest compounds (12 for monthly, 4 for quarterly, 1 for annually). Optionally add a regular contribution per compounding period — e.g. a monthly top-up — to see how ongoing deposits grow alongside the principal. The final amount and interest earned update instantly.
Formula
Example
Investing ৳1,00,000 at 8% annual interest, compounded monthly, for 5 years grows to roughly ৳1,49,000 — about ৳49,000 in interest earned. Adding ৳1,000 every month on top grows the total to roughly ৳2,22,000.
Understanding your result
The growth chart shows the balance at the end of each year. Because interest compounds, the balance grows faster in later years than in earlier ones, even though the rate stays the same. Regular contributions add further on top, since each one starts compounding from the period it is added.
Frequently Asked Questions
What compounding frequency should I use?
Use whatever your bank, DPS or savings scheme actually applies — most Bangladeshi bank fixed deposits compound monthly or quarterly. Check your deposit terms for the exact frequency.
Does this include any tax on interest income?
No — this shows gross interest before any tax, source deduction, or bank charges that may apply to your specific account.
Can I use this for a recurring monthly deposit (DPS)?
Yes — set "Additional Contribution Per Period" to your regular deposit amount and Compounds/Year to match how often you deposit (12 for monthly). This simulates the balance period by period, the same way a recurring deposit actually grows.