Compound Interest Calculator

What Is Compound Interest?

Compound interest is the process where interest is added not only to the original amount (the principal) but also to the interest already earned. This creates a snowball effect, helping your investment grow faster the longer you leave it untouched.

The basic formula for compound interest is:

A = P × (1 + r/n)nt

• A = Final amount (future value)
• P = Initial investment
• r = Annual interest rate (decimal)
• n = Number of compounding periods per year
• t = Number of years

Why Compound Interest Matters

The longer your money stays invested, the greater the effect of compound interest. Even small amounts can grow into significant savings if you stay consistent and patient. It’s one of the most powerful tools in personal finance.

How to Use the Calculator

1. Enter your initial investment amount.
2. Choose the annual interest rate (in %).
3. Select the number of years you plan to invest.
4. Choose how often the interest compounds (monthly, quarterly, annually, etc.).
5. Click "Calculate" to see the future value and total interest earned.

Example

If you invest $1,000 at an annual interest rate of 5% for 10 years, compounded monthly, you’ll have over $1,647 — without adding any more money!

Start Planning Today

Compound interest rewards those who start early. Use this calculator regularly to track your goals and estimate returns. It’s a smart way to plan for retirement, children’s education, or major financial milestones.

Want to explore more tools? Try our Profit, Margin and Markup Calculator or read our business guides to take control of your finances.