About this calculator
With compound interest, each period’s interest is added to the balance and earns interest itself. With no top-ups, the balance after t years is P × (1 + r/k)k·t, where r is the yearly rate and k is the number of compounding periods per year. Monthly contributions are added at the end of each month.
Worked example
10,000 at 6% a year, compounded monthly for 10 years, grows to 18,193.97 — 8,193.97 of it is interest. Compounded yearly, it would reach 17,908.48.
How to use the compound interest calculator
- Enter the starting amount.
- Enter the monthly contribution.
- Enter the interest rate (per year).
- Enter the years.
- Read the result — it updates as you type.
Frequently asked questions
How much does 10,000 grow to at 6% for 10 years?
Compounded monthly, about 18,193.97. Compounded yearly, about 17,908.48.
Does compounding more often make a big difference?
A little. Monthly compounding beats yearly compounding at the same rate, but the gap between monthly and daily is small.