Watch growth compound

Compound Interest Calculator Online

Project how an initial deposit, regular contributions and compounding interest grow over time, with a stacked chart and a full year-by-year breakdown.

Build your projection

Adjust any field and the results update instantly.

$
%
$
Final balanceIn 15 years
$0

Contributions plus compound growth.

Total contributions$0
Interest earned$0
Effective annual yield0%

Balance growth, year by year

Year-by-year breakdown

YearStart balanceContributionsInterestEnd balance

This projection assumes a constant rate and is for educational purposes only. It does not account for taxes, fees or market volatility.

How compound interest is calculated here

The calculator converts your annual rate and compounding frequency into an equivalent monthly growth rate, applies that growth every month, and adds your contribution on the schedule you choose—monthly at the end of each month, or annually at the end of each year. The chart and table separate your own money from the interest it earns.

Compare compounding frequency

See how monthly, quarterly or daily compounding changes results at the same stated annual rate.

Model real contributions

Add a recurring deposit on a monthly or annual schedule to see its long-term impact on growth.

Read the full timeline

Scroll the year-by-year table to see exactly how much interest accrues each year of the plan.

Compound interest calculator FAQ

How is compound interest calculated here?

The calculator converts your annual rate and compounding frequency into an equivalent monthly growth rate, then applies that growth every month and adds your contribution on the schedule you choose.

What compounding frequency should I choose?

Choose the frequency that matches your account, such as monthly for many savings accounts or annually for some bonds. More frequent compounding produces slightly higher growth at the same stated rate.

When are contributions added?

Monthly contributions are added at the end of each month. Annual contributions are added once at the end of each year.

What does the chart show?

The chart stacks your total contributions (principal plus deposits) at the bottom and the interest earned on top, so you can see how much of the final balance came from growth versus your own money.

Is this calculator private?

Yes. All projections run locally in your browser using JavaScript. Nothing you enter is uploaded or stored on a server.

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