Compound Interest Calculator

Project future balance, total contributions, and estimated earnings from an initial deposit and recurring savings.

Initial principalMonthly contributionAnnual return (%)Years

Compounding

Estimated future value

￥50,970

Total contributions

￥34,000

Estimated earnings

￥16,970

How compound growth works

Compound growth adds returns to the original balance and to prior gains. The longer the horizon, the stronger the snowball effect becomes.

What is the difference between simple and compound interest? expand_more

Compound interest earns returns on earlier returns, while simple interest only applies to the original principal.

Do monthly contributions matter a lot? expand_more

Yes. Over longer periods, consistent contributions can materially increase the final balance.