Compound Interest Calculator

Calculate compound interest online for free. See how your investments grow over time.

✓ Free✓ No sign-up✓ Works in browser

AdSense

728×90 Leaderboard

Initial Investment

Annual Interest Rate (%)

Time Period (years)

Monthly Contribution

Compound Frequency

Future Value

$167,072

Total Deposited$58,000

Interest Earned$109,072

Growth over time

Yr 0

$10,000

Yr 2

$16,916

Yr 4

$25,027

Yr 6

$34,540

Yr 8

$45,698

Yr 10

$58,786

Yr 12

$74,136

Yr 14

$92,139

Yr 16

$113,256

Yr 18

$138,023

Yr 20

$167,072

DepositedInterest

AdSense

336×280 Rectangle

QuickBooks

Smart accounting for small businesses

Partner

Track income, expenses, invoices and payroll. 7M+ businesses rely on QuickBooks.

50% Off for 3 Months

How to Use This Tool

Enter Your Investment Details

Enter your initial investment amount, expected annual return rate, and time period in years.

Add Monthly Contributions

Optionally enter a monthly contribution amount to see how regular investing accelerates your wealth growth through dollar-cost averaging.

Read Your Results

See the future value of your investment, total amount deposited, and total interest earned. The bar chart shows how your money grows year by year.

Related Tools

Retirement Calculator

Frequently Asked Questions

What is compound interest?

Compound interest is interest calculated on both the initial principal and the accumulated interest from previous periods. Einstein reportedly called it the eighth wonder of the world — money grows exponentially, not linearly.

What is a realistic return rate to use?

The S&P 500 index has historically returned approximately 10% annually before inflation, or about 7% after inflation. For conservative estimates, use 6-7%. For bonds, use 3-4%.

How does compounding frequency affect growth?

More frequent compounding (daily vs annually) produces slightly higher returns. Daily compounding earns slightly more than monthly, which earns more than annual. The difference becomes significant over long time periods.

What is the Rule of 72?

Divide 72 by your annual interest rate to estimate how many years it takes to double your money. At 8% return, your money doubles in about 9 years (72 ÷ 8 = 9).

About Compound Interest Calculator

Our Compound Interest Calculator is a free, fast, and privacy-friendly tool that works entirely in your browser. No files are ever uploaded to our servers — all processing happens locally.

Unlike competitors that impose daily limits or require account creation, FreeToolKit gives you unlimited access with zero sign-up. Whether you are a developer, student, designer, or business professional, this tool is built to save you time.