Compound Interest Calculator
See how compound interest grows a single deposit over time. Unlike simple interest, compound interest earns interest on past interest, so time and the compounding frequency matter as much as the rate itself.
Disclaimer: Results are estimates for planning only and are not financial advice. Interest rates, fees, taxes, and lender terms vary. Check with your bank or a qualified financial adviser before borrowing or investing.
How to use
- Enter the initial deposit.
- Enter the annual interest rate.
- Choose how often interest compounds: yearly, quarterly, monthly, or daily.
- Enter the number of years.
- Click Calculate to see the future value and the interest earned.
Frequently asked questions
What is the compound interest formula?
Future value = P x (1 + r/n)^(n x t), where P is the principal, r is the annual rate, n is the number of compounding periods per year, and t is the years.
Why does monthly compounding beat yearly compounding?
Interest is added sooner, so it starts earning interest earlier. The difference is small at low rates but grows with larger amounts and longer periods.
Is this the same as a savings account return?
Only if the rate stays fixed and no fees or withdrawals apply. Real account rates change, and taxes may apply to interest.
How can I use this for a goal?
Work backward: try different starting amounts and years until the future value reaches your goal, then check whether the monthly saving needed is realistic.