--- title: "APY / Effective Yield Calculator" description: "Convert a nominal interest rate and compounding frequency into APY (effective annual yield) and an illustrative one-year ending value on your deposit." canonical: https://www.getswoopr.com/tools/apy-effective-yield-calculator/ source: "Swoopr Investment: https://www.getswoopr.com" --- Savings & Growth Tools # APY / Effective Yield Calculator Turn a nominal interest rate and compounding frequency into the effective annual yield you actually earn. Enter a nominal annual interest rate and how often it compounds to see the resulting APY (Annual Percentage Yield), plus an illustrative one-year ending value if you enter a starting balance. Search guides, glossary terms, tools and answers Search Learn APY vs. interest rate first Go to calculator ![Focused image of a person using a calculator amidst financial documents and charts.](https://www.getswoopr.com/images/hero/tools-apy-effective-yield-calculator.webp) *Photo by [Kindel Media](https://www.pexels.com/@kindelmedia) via [Pexels](https://www.pexels.com/photo/close-up-shot-of-a-person-using-calculator-7688523/)* ## Direct Answer > APY (Annual Percentage Yield) is the effective annual rate an account actually earns once compounding is factored in: APY = (1 + nominal rate ÷ compounding periods per year)^(compounding periods per year) − 1. It is always equal to or greater than the stated nominal rate, and it lets you compare two accounts with different compounding schedules on an apples-to-apples basis. This calculator is an illustrative, single-year projection: it assumes a constant nominal rate held for exactly one year with no withdrawals or additional deposits. It is not a forecast or a recommendation. ## APY Calculator Results are illustrative estimates based on the numbers you enter, assuming a constant rate held for one year with no withdrawals. Not investment advice, a forecast, or a recommendation. All calculation happens locally in your browser; nothing is sent to a server. ![Close-up of a woman using a calculator and phone at her office desk.](https://www.getswoopr.com/images/accent/tools-apy-effective-yield-calculator-accent-1.webp) *Photo by [Anna Tarazevich](https://www.pexels.com/@anntarazevich) via [Pexels](https://www.pexels.com/photo/woman-using-a-black-and-red-smartphone-and-calculator-5196820/)* Rate & Compounding Nominal annual interest rate (%) The stated annual rate before compounding. Must be 0 or greater. Compounding frequency (periods per year) How many times per year interest compounds. Common values are 1 (annual), 2 (semiannual), 4 (quarterly), 12 (monthly), and 365 (daily), but any positive whole number is accepted. Starting balance ($) (optional) Enter an amount to see an illustrative one-year ending value and dollar interest earned. Leave blank to see APY only. Calculate Clear ### Results #### APY (Effective Annual Yield) N/A (1 + nominal rate ÷ n)n − 1 Nominal annual rate entered N/A Compounding periods per year N/A Illustrative one-year ending value N/A Illustrative interest earned (1 year) N/A Results assume the nominal rate stays constant for the full year with no withdrawals or additional deposits. They don't account for rate changes, taxes, fees, or account minimums. Use them as a planning baseline, not a guarantee. ## Methodology The calculator applies the formula below directly to your inputs: APY = (1 + Nominal rate ÷ n) n − 1 Illustrative ending value = Principal × (1 + APY) Illustrative interest earned = Illustrative ending value − Principal - **Nominal rate** is the stated annual rate before compounding, entered as a percentage (e.g. 5 for 5%). - **n** is the number of compounding periods per year (1 for annual, 12 for monthly, 365 for daily, and so on). - **APY** is always equal to or greater than the nominal rate for any compounding frequency greater than one, because interest starts earning interest on itself within the year. - As compounding frequency increases without bound, APY approaches the continuous-compounding limit, erate − 1, but the gain from compounding more often than daily is small in practice. ### Assumptions and limitations - Assumes the nominal rate is held constant for exactly one year. Real deposit account rates, especially on high-yield savings accounts and money market accounts, can change at any time. - Assumes no withdrawals and no additional deposits during the year beyond the starting balance you enter. - Does not account for taxes on interest income, account fees, or minimum-balance requirements. - Not a forecast, a guarantee, or a recommendation to open any specific account. - All calculation happens locally in your browser using the inputs on the page; nothing is fetched from or sent to a server. ## Related Reading - [Cash & Cash Equivalents: hub](https://www.getswoopr.com/cash-and-cash-equivalents/) - [APY vs. Interest Rate Explained](https://www.getswoopr.com/cash-and-cash-equivalents/apy-vs-interest-rate/) why the two numbers differ and which one to compare. - [High-Yield Savings Accounts](https://www.getswoopr.com/cash-and-cash-equivalents/high-yield-savings-accounts/) where APY is the headline number to compare. - [Certificates of Deposit (CDs)](https://www.getswoopr.com/cash-and-cash-equivalents/certificates-of-deposit-cds/) another common account type quoted in APY. - [CD Ladder Builder](https://www.getswoopr.com/tools/cd-ladder-builder/) plan a CD ladder using an assumed APY across rungs. - [Free Stock & Crypto Trading Tools](https://www.getswoopr.com/tools/) the section this guide belongs to - [Balance Transfer Calculator: The Fee Against the Interest It Buys Out](https://www.getswoopr.com/tools/balance-transfer-calculator/) a companion guide in this cluster - [Company Metric Comparison Dashboard](https://www.getswoopr.com/tools/company-fundamentals-comparison/) a companion guide in this cluster - [Compound Growth & Contribution Calculator](https://www.getswoopr.com/tools/compound-growth-calculator/) a companion guide in this cluster - [Credit Card Payoff Calculator: What the Minimum Payment Actually Costs](https://www.getswoopr.com/tools/credit-card-payoff-calculator/) a companion guide in this cluster ## FAQ ### What is APY? APY (Annual Percentage Yield) is the effective annual rate an account actually earns once compounding is accounted for. APY = (1 + nominal rate ÷ compounding periods per year)^(compounding periods per year) − 1. It is always equal to or greater than the nominal rate, because it captures interest earned on interest already credited during the year. ### Why is APY higher than the nominal interest rate? The nominal rate is the stated annual rate before compounding. APY reflects what actually accrues once interest starts earning interest on itself within the year. The more frequently interest compounds (monthly or daily versus annually), the larger the gap between the nominal rate and APY, though the effect shrinks at very high compounding frequencies as it approaches the continuous-compounding limit. ### Does compounding frequency matter for APY? Yes. A higher compounding frequency (daily versus monthly versus annually) produces a higher APY for the same nominal rate, because interest is credited and starts compounding sooner. Annual compounding is the one case where APY exactly equals the nominal rate, since there's only a single compounding period. ### Is this calculator's output a guaranteed return? No. This calculator produces an illustrative, single-year projection that assumes the nominal rate stays constant for the full year and that no withdrawals or additional deposits occur. Real deposit accounts can change their rate at any time, and actual returns will differ if the rate changes or the balance moves. It is not a forecast or a recommendation.