APY Calculator

Adjust the calculator values below

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Annual percentage yield (APY) Effective annual return after compounding
Financial Calculator

APY Calculator

Use this APY with initial deposit, annual percentage rate (apr), and compound frequency to estimate costs, returns, payments, or rates and get a...

APY is different from a nominal annual percentage rate because APY includes the effect of earning interest on earlier interest.

What is APY?

Annual percentage yield measures the effective return earned over one year after compounding is included. It is useful when comparing deposit products that quote similar rates but compound at different intervals.

APY is different from a nominal annual percentage rate because APY includes the effect of earning interest on earlier interest.

How does this APY calculator work?

Enter the nominal annual rate and compounding frequency to calculate APY. You can also change APY to find the equivalent nominal rate.

The deposit and term fields translate the rate into an estimated ending balance and interest earned.

How to calculate annual percentage yield

The calculation uses APY = (1 + APR / n)^n - 1, where n is the number of compounding periods per year.

Rates are converted from percentages to decimals before applying the formula and converted back for display.

Difference between APR and APY

APR commonly describes a nominal yearly rate, while APY shows the effective yearly change after compounding. They are equal when compounding occurs only once per year.

When compounding happens more frequently, APY will normally be higher than the corresponding nominal APR.

Frequently asked questions

Common questions about APY, assumptions, costs, rates, and how to read the result before making a money decision.

What numbers should I include in APY?

Include the amounts, rates, dates, fees, and recurring costs that belong to the same financial decision. Excluding one major cost can make the result look better than the real outcome.

How do rates affect APY?

Rates can change borrowing cost, investment growth, tax, discount, or return. Check whether the rate is annual, monthly, fixed, variable, simple, or compounded before using it.

Why does the time period matter for APY?

The time period affects compounding, repayment, inflation, fees, and cash flow. A monthly assumption should not be mixed with an annual one unless it has been converted correctly.

Can I use APY for budgeting?

Yes, as a planning estimate. For a real budget, include cash flow timing, taxes, fees, insurance, maintenance, and any expenses that the calculator does not ask for directly.

Why might my APY estimate be wrong?

Common causes are outdated rates, missing fees, tax assumptions, rounded numbers, optimistic growth, or mixing values from different periods or offers.

What should I review before acting on APY?

Review the source numbers, compare them with official statements or quotes, and test a conservative scenario so the decision still makes sense if conditions change.