Local · Private · Free

Compound Interest Calculator

See how savings snowball over time. Enter a principal, rate, and time horizon and get a future value, total contributions, interest earned, a year-by-year table, and a growth chart, all computed on your device with no signup.

Your plan

Currency

Initial principal

What you start with today.

Regular contribution

Added at the end of each period.

Annual interest rate %

Time horizon (years)

Compounding frequency How often interest is added back to the balance.

Calculated locally, nothing is sent anywhere.

The eighth wonder of the world

Compound interest pays you on your interest, so balances accelerate the longer you leave them. Time and consistency usually matter more than a high rate, small monthly contributions started early often beat larger sums started late. Every figure here is computed in your browser, so your numbers stay private. Planning bigger? Digital Heroes can help.

About Compound Interest Calculator

Compound Interest Calculator is a free, private tool by Digital Heroes that runs entirely in your browser. Enter a starting balance, annual rate, time horizon, and optional regular contributions to instantly see your projected future value, total contributions, and interest earned. A year-by-year breakdown table and an interactive growth chart let you visualise exactly how interest compounds over time. Everything is calculated on your device. No signup, no upload, no limits.

What you can do

Project a lump-sum investment over any horizon up to 100 years with a chosen annual rate.

Add monthly or yearly contributions and see how consistent saving accelerates growth.

Compare compounding frequencies (monthly, quarterly, or annually) to see the difference in end balance.

Read the year-by-year table showing start balance, contributions, interest earned, and end balance for every year.

Export the full schedule as a CSV file for use in a spreadsheet or financial model.

Switch currency symbols (USD, EUR, GBP, INR, and more) to match your region.

How to use Compound Interest Calculator

Open Compound Interest Calculator in your browser. No signup required.

Enter your initial principal (the amount you have today) and an annual interest rate.

Set a time horizon in years and, optionally, a regular contribution (monthly or yearly).

Choose a compounding frequency (monthly, quarterly, or annually) that matches your account.

Results update instantly. Scroll down to read the year-by-year table or click Export CSV to save the schedule.

Frequently asked questions

Is Compound Interest Calculator free?

Yes, Compound Interest Calculator is completely free for everyone. No sign-up, no account and no usage limits.

Is it private? Are my files uploaded anywhere?

No. Compound Interest Calculator runs entirely in your browser on your own device, so your data never leaves your computer and nothing is uploaded to a server.

Does it work offline?

Yes. This tool is a Progressive Web App, once the page has loaded it keeps working offline, and you can install it as an app from your browser.

Do I need to install anything or create an account?

No. Just open the page and start using it. Installing it as an app is optional and only adds offline convenience.

What does Compound Interest Calculator do?

It calculates the future value of an investment or savings plan given a principal, annual rate, time horizon, and regular contributions. It shows total contributions vs. interest earned, a year-by-year breakdown table, and a growth chart. You can also export the full schedule as a CSV file.