Fastway Tools

Compound Interest Calculator

Final amount$2,395.08
Total invested$2,200.00
Total interest$195.08

The Compound Interest Calculator shows how an investment grows over time when interest is earned on both the original amount and the interest already accumulated. Enter an initial amount, an optional monthly contribution, the interest rate (monthly or yearly) and the period, and the tool instantly projects the final balance, the total you invested and the interest earned, plus a year-by-year breakdown. It is perfect for planning savings, retirement or any long-term goal, and it runs entirely in your browser so your figures stay private.

How to Use the Calculator

  1. Enter the initial amount and an optional monthly contribution.
  2. Set the interest rate (per month or per year) and the period.
  3. Read the final amount, total invested and interest, plus the yearly breakdown.

Benefits and Use Cases

  • Plan savings, investments and retirement goals with realistic projections.
  • See the impact of regular monthly contributions and of time on compounding.
  • Runs entirely in your browser — your financial figures are never uploaded.

FAQ

How is compound interest calculated?

The balance grows on both the principal and previously earned interest. This tool also adds your monthly contributions and compounds everything month by month.

Can I enter a yearly rate?

Yes. Switch the rate to "per year" and it is converted to an equivalent monthly rate automatically.

Is my data saved?

No. All calculations run in your browser and nothing is sent to a server.