Compound Interest Calculator

This free compound interest calculator shows how your money grows over time with compounding, recurring deposits, tax adjustments, and multiple currencies. Solve for Principal, Rate, Years, or Maturity Amount — enter any 3, get the 4th.

Fill in any 3 of the 4 fields below (Principal, Rate, Years, Final Amount) and leave the one you want solved for empty.

Note: when a Recurring Deposit is set, the "solve for missing field" feature only works for Final Amount — Principal, Rate, and Years must all be filled in. Once calculated, deposit amounts can be edited directly in the table below for each period — click Solve again to reset them back to a uniform schedule. With Monthly frequency, click ▶ on a year row to expand it into its 12 months.

Year Total Amount Interest Rate Deposits Added Interest Earned Tax Deducted Total ROI % Total Amount as % of Initial

How Your Fund Grows: Principal vs Interest

How This Compound Interest Calculator Works

Compound interest means you earn interest not only on your original principal, but also on the interest that has already accumulated. Over long periods, this compounding effect can make a much bigger difference than simple interest — the formula used by this compound interest calculator is A = P(1 + r)t, where P is your principal, r is the interest rate, and t is the number of periods.

Recurring Deposits

Adding a monthly or yearly recurring deposit on top of your principal accelerates growth further, since each new deposit also starts earning compound interest from the moment it's added. This calculator lets you edit each individual deposit amount after the initial calculation, so you can model irregular contributions — for example, a year where you deposited more or less than usual.

Tax on Interest

Many jurisdictions tax interest income annually or, less commonly, apply withholding on a monthly basis. Enabling Tax Reduction here deducts a percentage from the interest earned each period (not from your principal or deposits), which slightly reduces the compounding effect since the taxed portion no longer earns further interest.

Frequently Asked Questions About This Compound Interest Calculator

How do I find the interest rate I need to reach a savings goal?

Enter your Principal, Years, and target Final Amount, and leave the Annual Rate field empty. Click Solve & Calculate, and the required rate will be calculated automatically and filled into the Rate field.

Can I use this compound interest calculator with currencies other than US Dollars?

Yes. Select your currency from the dropdown — major currencies including EUR, GBP, JPY, INR, LKR, AUD, CAD, CNY, CHF, SGD, AED, NZD, ZAR, and SEK are supported. When a non-USD currency is selected, enter the current exchange rate against USD for accurate conversion.

What's the difference between monthly and yearly compounding?

Monthly compounding applies interest 12 times a year using an equivalent monthly rate derived from your annual rate, which produces a smoother, more granular growth curve than compounding once a year. Both methods will produce the same result at year-end if no deposits or tax are involved — the difference becomes visible once you add monthly deposits or monthly tax deductions.

Is this compound interest calculator free to use?

Yes, this compound interest calculator is completely free with no signup required. All calculations run directly in your browser.