Compound Interest Calculator
See how your money grows over time with compound interest — enter your principal, rate, time period and compounding frequency.
Calculate compound growth
Rates are annual and user-supplied — nothing is pre-filled from a bank.
Result
Formula used
A = P (1 + r/n)n×t
- A
- Final amount
- P
- Principal
- r
- Annual interest rate (decimal)
- n
- Compounding periods per year
- t
- Time in years
How to use this calculator
- Enter your starting principal amount.
- Enter the annual interest rate as a percentage.
- Enter the number of years and choose a compounding frequency.
- Press Calculate to see your final amount and total interest.
FAQ
Frequently asked questions
What is compound interest?
Compound interest is interest calculated on both the initial principal and the accumulated interest from previous periods, so growth accelerates over time.
What is the compound interest formula?
A = P(1 + r/n)^(n×t), where P is principal, r is annual rate, n is compounding periods per year, and t is time in years.
What compounding frequency should I choose?
Use the frequency stated by your bank or investment product — common options are annually, semi-annually, quarterly, monthly, or daily.
Does more frequent compounding always mean more interest?
Yes, at the same nominal rate, more frequent compounding produces a slightly higher effective return, though the difference is usually small.