CD Calculator
Calculate the maturity value and yield (APY) of a certificate of deposit.
Maturity Value
Total Interest Earned
APY (Annual Percentage Yield)
What Is a Certificate of Deposit?
A certificate of deposit (CD) is a savings product offered by banks and credit unions that pays a fixed interest rate in exchange for leaving a lump sum untouched for a set term. Because the rate is locked in for the full term, a CD offers predictable, low-risk growth, with the trade-off that withdrawing money early usually triggers a penalty.
How the Maturity Value Is Calculated
The maturity value uses the standard compound interest formula: Maturity = P × (1 + r / k)k × t, where P is the deposit, r is the annual rate as a decimal, k is the number of compounding periods per year (daily = 365, monthly = 12, quarterly = 4, annually = 1), and t is the term in years. The total interest earned is simply the maturity value minus your original deposit.
APY vs. Nominal Interest Rate
The nominal rate (sometimes called the stated or annual interest rate) does not, by itself, tell you how much you will actually earn, because it ignores compounding. The Annual Percentage Yield (APY) is the effective annual rate of return once compounding is taken into account, calculated as APY = (1 + r / k)k − 1. The APY is always equal to or greater than the nominal rate, and it lets you compare CDs fairly even when they compound on different schedules.
How Compounding Frequency Affects Yield
The more often interest is compounded, the more you earn, because each compounding event adds interest that itself begins earning interest. A CD that compounds daily produces a slightly higher APY than one with the same nominal rate compounding annually. The effect is real but modest: at typical CD rates the difference between daily and annual compounding is usually a small fraction of a percentage point, which is why the APY is the most useful single number for comparison shopping.
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Disclaimer: This calculator provides estimates for educational purposes only. Results do not account for taxes, early-withdrawal penalties, fees, or changes in interest rates. Actual returns may vary. Consult with a qualified financial advisor before making financial decisions.