What is compound interest?

Compound interest is interest earned on both your original investment and on previously earned interest, causing your money to grow at an accelerating rate over time.

Which compounding frequency should I choose?

Use the frequency your bank or investment actually uses - savings accounts often compound daily, many bonds semi-annually, and most funds monthly. More frequent compounding produces slightly higher returns.

Do monthly contributions affect the result?

Yes. Regular contributions are added each month and immediately begin earning compound interest, which significantly increases the final value over long periods.

Compound Interest Calculator

Calculate compound interest growth on investments with monthly contributions. See future value across yearly to daily compounding.

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About Compound Interest Calculator

The compound interest calculator projects how an investment grows when interest is added to the principal and earns interest itself.

Compound interest is the engine of long-term wealth — reinvesting returns turns modest savings into substantial sums over decades. This tool projects growth at your chosen rate, frequency, and term.

When to Use Compound Interest Calculator

Use it to model retirement savings growth, to compare accounts by compounding frequency, or to show the value of starting early.

Pro Tip

Compounding frequency matters — monthly compounding beats annual at the same nominal rate; check which your account offers.

Key Features

Processes Initial Investment, Monthly Addition, Interest Rate, Time Period (Years) directly in your browser
Produces future value, interest earned instantly
Completely free with no usage limits
No registration or account required

How to Use

Provide the required inputs (Initial Investment, Monthly Addition, Interest Rate, Time Period (Years)).
The tool processes everything locally in your browser and instantly produces the following results: Future Value, Interest Earned.
Review the result, then copy it to your clipboard or download the output file directly from this page.

Privacy note: Compound Interest Calculator runs 100% in your browser. Your data is never uploaded to any server, so nothing is stored or shared.

Benefits

Your data never leaves your device when using Compound Interest Calculator - everything runs locally
Get accurate results in seconds
Works on desktop, tablet, and mobile
No software download or installation needed