Compound Interest Calculator
See how your money grows when interest is earned on both your original amount and past interest.
Enter your details below.
How to use
- Enter the starting amount you plan to invest or save.
- Enter the annual interest rate, the number of years, and how often interest is compounded.
- Press Calculate to see the final amount and the total interest earned.
About this tool
This calculator works out the future value of a lump sum that earns compound interest. It uses the formula A = P(1 + r/n) raised to the power of n times t, where P is the starting amount, r is the annual interest rate, n is how many times interest is added each year, and t is the number of years. Compounding more often means interest starts earning interest sooner, so the final amount grows faster over time.
Frequently asked questions
What is the difference between simple and compound interest?
Simple interest is paid only on the original amount, while compound interest is paid on the original amount plus any interest already earned, so growth speeds up over time.
Does compounding more often make a big difference?
Yes, over long periods it can add up, because interest is added to your balance sooner and then earns interest itself. Monthly compounding usually gives a slightly higher result than annual compounding at the same rate.