APY calculator

Turn an interest rate (APR) into the annual percentage yield (APY) for any compounding, or work back from an APY. Add a deposit to see the interest it earns.

By the Calcist team · Checked against known answers · Updated October 28, 2026

Private: calculated on your device. Nothing you type is sent anywhere.

Estimates for planning, not financial, tax or legal advice. Figures use US rules unless the page says otherwise.

Next: Adding money every month? The savings calculator works from an APY. Locking it in? The CD calculator shows the early withdrawal penalty.

What APY means

APY stands for annual percentage yield. It's the interest a savings account, CD or money market account pays in one year, as a percent of your balance, including the interest you earn on interest. APR (or "interest rate") is the stated yearly rate before compounding. If interest is added only once a year, the two are the same. If it's added monthly or daily, APY is a little higher.

US banks and credit unions have to quote APY on deposit accounts under the Truth in Savings Act and its rule, Regulation DD. That makes APY the fair way to compare two accounts that compound differently.

How APY is calculated

APY = (1 + r ÷ n)ⁿ − 1

r is the APR as a decimal and n is the number of times interest compounds in a year (365 for daily, 12 for monthly, 4 for quarterly). For continuous compounding, APY = e^r − 1. To go the other way:

APR = n × ((1 + APY)^1/n − 1)

Regulation DD defines APY from the interest actually paid. For a term of one year it reduces to interest ÷ principal:

APY = 100 × [(1 + interest ÷ principal)^{365 ÷ days in term} − 1]

Regulation DD's own example: $61.68 of interest on $1,000 over a 365-day year is an APY of 6.17%.

Worked example

An account pays 5% APR compounded monthly. APY = (1 + 0.05 ÷ 12)¹² − 1 = 0.051162, or 5.12%. On a $10,000 deposit that's $511.62 in the first year, versus $500.00 with yearly compounding.

5% APR compounded	APY	Interest on $10,000 in 1 year
Daily (365)	5.1267%	$512.67
Monthly (12)	5.1162%	$511.62
Quarterly (4)	5.0945%	$509.45
Yearly (1)	5.0000%	$500.00

Going the other way, a 5% APY with monthly compounding needs an APR of 4.889%. The difference between daily and monthly compounding is about one cent per $100 a year, so when two banks quote APY, just compare the APYs.

Limitations

Rates change. Savings rates are usually variable. This calculator assumes the rate stays the same for the whole time you enter. There's no live rate data here; type in the rate your bank quotes.
No deposits or withdrawals. It shows one lump sum. For regular deposits use the savings calculator; for a CD with an early withdrawal penalty use the CD calculator.
Tax. The results are before any tax on the interest.
Loans are different. A loan's APR is its own measure of borrowing cost. See the APR calculator.

Sources

CFPB: Regulation DD (Truth in Savings), Appendix A – Annual Percentage Yield Calculation

How we checked this

Before every update, this calculator is run in a real browser with these known answers, and it must match all of them:

5% APR compounded monthly: APY 5.11619%, $511.62 on $10,000 in a year ✓
5% APR compounded daily: $512.67 on $10,000 in a year ✓
Reverse: a 5% APY with monthly compounding needs a 4.889% APR ✓
4.5% APR compounded daily on $25,000 for 2 years earns $2,354.21 ✓
Edge case: a 0% rate gives a 0% APY ✓

Last checked October 26, 2026. Spotted something wrong? The math is done in your browser with the formula shown on this page, so you can check any result by hand.

Add this calculator to your website (free)

Paste this code into any web page. The calculator works on your page, resizes itself, has no ads and no tracking, and nothing your visitors type is sent anywhere. More about embedding.

<iframe src="https://calcist.com/embed/apy-calculator/" title="APY calculator" width="100%" height="640" loading="lazy" style="border:0;max-width:760px"></iframe>
<p style="font:14px/1.4 sans-serif;margin:4px 0 0"><a href="https://calcist.com/apy-calculator/">APY calculator</a> by Calcist</p>
<script src="https://calcist.com/embed.js" async></script>

Questions people ask

What does APY mean?

Annual percentage yield: the percent your money earns in a year once compounding is counted. A 5% rate compounded monthly is a 5.12% APY.

What is the difference between APY and APR?

APR is the stated yearly rate before compounding. APY includes the interest earned on interest, so it's equal to APR with yearly compounding and higher with monthly or daily compounding.

How do I calculate APY?

APY = (1 + r/n)^n − 1, with r the rate as a decimal and n the compounding periods per year. For 4.5% compounded daily: (1 + 0.045/365)^365 − 1 = 4.60%.

How much interest will $10,000 earn at 5% APY?

$500 in one year, because APY already includes compounding. Over two years it's $1,025, since the second year earns interest on $10,500.

Is daily compounding much better than monthly?

Only slightly. At 5%, daily compounding gives a 5.127% APY and monthly gives 5.116%, about $1 a year on $10,000.

Related calculators

Savings calculatorBank savings with deposits at an APY, after tax and in today's dollars.CD calculatorCD interest and value at maturity from APY or APR, with an early withdrawal penalty.Compound interest calculatorGrowth with monthly deposits, daily to yearly compounding.APR calculatorThe true APR of a loan with fees, by the Regulation Z method.