Calculate the Annual Percentage Yield and growth of your Certificate of Deposit.
Daily
Monthly
Quarterly
Semi-Annually
Annually
Months
Years
Annual Percentage Yield (APY)0.00%
Final Balance$0.00
Total Interest Earned$0.00
Understanding Your CD Growth
A Certificate of Deposit (CD) is a savings account that holds a fixed amount of money for a fixed period of time, such as six months, one year, or five years. In exchange for keeping the money in the CD, the issuing bank pays interest.
What is APY?
Annual Percentage Yield (APY) reflects the real rate of return on your investment by taking into account the effect of compounding interest. Unlike the nominal interest rate, APY shows you how much you will actually earn in a year if the interest is reinvested.
The Importance of Compounding Frequency
Compounding occurs when the interest you earn is added back to your principal balance, and then you earn interest on that new, larger balance. The more frequently interest compounds (e.g., daily vs. annually), the higher your APY will be, even if the nominal interest rate stays the same.
Practical Example
If you deposit $10,000 into a 12-month CD with a 5.00% nominal interest rate compounded monthly:
Nominal Rate: 5.00%
Compounding Periods: 12 per year
Effective APY: 5.116%
Total Interest Earned: $511.62
Final Balance: $10,511.62
By using this APY calculator, you can compare different CD offers from various banks to see which one provides the best return on your savings, regardless of how they quote their interest rates.
function calculateCD() {
var principal = parseFloat(document.getElementById('initialDeposit').value);
var nominalRate = parseFloat(document.getElementById('nominalRate').value);
var compoundsPerYear = parseInt(document.getElementById('compoundingFrequency').value);
var termLength = parseFloat(document.getElementById('termLength').value);
var termUnit = document.getElementById('termUnit').value;
if (isNaN(principal) || isNaN(nominalRate) || isNaN(termLength) || principal <= 0 || nominalRate < 0 || termLength <= 0) {
alert("Please enter valid positive numbers for all fields.");
return;
}
// Convert nominal rate to decimal
var r = nominalRate / 100;
// Calculate APY: APY = (1 + r/n)^n – 1
var apy = Math.pow(1 + (r / compoundsPerYear), compoundsPerYear) – 1;
var apyPercentage = apy * 100;
// Convert term to years for balance calculation
var t = (termUnit === 'months') ? termLength / 12 : termLength;
// Calculate Final Balance: A = P(1 + r/n)^(nt)
var finalBalance = principal * Math.pow(1 + (r / compoundsPerYear), compoundsPerYear * t);
var totalInterest = finalBalance – principal;
// Display results
document.getElementById('apyResult').innerText = apyPercentage.toFixed(3) + "%";
document.getElementById('balanceResult').innerText = "$" + finalBalance.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById('interestResult').innerText = "$" + totalInterest.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById('resultsArea').style.display = 'block';
}