How does compound interest work?

Interest is added to your balance, and the next interest is calculated on the larger balance – so you earn interest on your interest. The more often it compounds and the longer you wait, the faster the balance grows.

What's the difference between the interest rate and APY?

The rate is the nominal yearly rate; the APY (effective annual rate) includes the effect of compounding within the year. 12 % compounded monthly is an APY of about 12.68 %.

What is the rule of 72?

Divide 72 by the yearly return to estimate how many years it takes money to double: at 6 % that's about 12 years. The calculator shows the exact doubling time.

Why show the value in today's money?

Inflation makes money worth less over time. With inflation set, the calculator divides the future balance by the rise in prices, so you can see what it will actually buy.

Compound Interest Calculator – Savings Growth with Monthly Deposits

See how savings grow with compound interest: a starting amount, monthly or yearly deposits, any compounding, rising contributions and inflation. Year-by-year table, chart and time to reach a goal – free, nothing uploaded.

Your numbers stay on this device – nothing is sent anywhere.

Starting amountRegular depositDeposit everyCurrencyAnnual interest rate (%)CompoundingYearsDeposits at theRaise deposits each year by (%)Inflation per year (%)Savings goal (optional)

Balance after 20 years$144,572.72

You pay in: $58,000.00
Interest earned: $86,572.72
In today's money: $144,572.72
Effective annual rate (APY): 7.229 %

At this rate, money doubles in about 9.9 years.

Before tax and fees, at a constant rate. Real returns vary – this isn't financial advice.

A free compound interest calculator for savings, investments and retirement plans. Enter a starting amount, a regular monthly or yearly deposit, the interest rate and how often it compounds, and see the balance year by year, how much of it you paid in and how much is interest. Deposits can come at the start or end of each period and rise every year with your salary, inflation shows the result in today's money, and a savings goal tells you exactly when you'll reach it. The chart, the year-by-year table and a CSV download make it easy to compare scenarios. Everything is calculated in your browser.

Compound Interest Calculator – Savings Growth with Monthly Deposits

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