Work out the maturity value, total interest and effective annual yield of a fixed-term certificate of deposit, and compare how daily, monthly, quarterly and annual compounding change the result.
A CD ladder splits the deposit into equal rungs that mature in successive years. The term above is the longest rung; each rung below it is one year shorter. Every rung is assumed to earn the same rate.
Advanced: currency symbol
The lower band is the money you put in; the green band on top is interest. The curve bends upward because each period earns interest on the interest already added.
| End of year | Interest added that year | Interest so far | Balance |
|---|
Each row shows how much interest was added in that year and the running balance at the year's end.
| Interest is added | Value at maturity | Interest earned | Effective yield (APY) |
|---|
Same deposit, rate and term at each compounding frequency. More frequent compounding pays slightly more, because interest starts earning interest sooner. The row matching your choice is highlighted.
For beginners: how to read this result
Describe the task to the AI assistant and continue from the result.
Open AI assistant →To get a result, pick a preset or enter your own figures: the deposit amount, the annual interest rate, and the term as whole years plus any extra months. Choose how often interest is added with the compounding buttons, and the calculator returns the value at maturity, the total interest earned and the effective annual yield.
How the maturity value is worked out
A certificate of deposit grows by compounding: interest is added at a set frequency, and from then on that interest earns interest too. The maturity value equals the deposit multiplied by one plus the annual rate divided by the number of compounding periods per year, all raised to the power of the periods per year times the number of years. Daily compounding uses 365 periods a year, monthly uses 12, quarterly uses 4 and annual uses 1. The total interest earned is simply the maturity value minus the original deposit.
What the effective annual yield means
The annual percentage yield, or APY, is the true yearly growth once compounding is counted. It equals one plus the rate divided by the periods per year, raised to the power of the periods per year, minus one. Because interest starts earning interest within the year, the APY sits a little above the plain quoted rate, and more frequent compounding lifts it slightly higher. The comparison table shows the maturity value, interest and APY side by side for all four frequencies on the same deposit and rate.
Single CD and CD ladder modes
In Single CD mode the whole deposit is locked for one term. In CD ladder mode the deposit is split into equal rungs that mature in successive steps: the term you enter is the longest rung, and each rung below it matures one step earlier. The number-of-rungs field appears only in ladder mode. A ladder gives you access to part of the money sooner instead of locking everything until one distant date. In this calculator every rung is assumed to earn the same rate, so treat the laddered total as a planning estimate rather than a forecast of real reinvestment.
Reading the chart and the year-by-year table
The growth chart shows the original principal as a lower band and the accrued interest as a band on top, with the curve bending upward as compounding accelerates. In ladder mode dashed lines mark where each rung matures. The year-by-year table lists the interest added in each year and the running balance, so you can see exactly how the deposit builds up rather than just the final figure.
What is not included
This is an estimate that assumes one constant rate held for the full term. It does not account for tax on interest income, early-withdrawal penalties, inflation, account or brokerage fees, variable or promotional bump-up rates, or deposit-insurance limits. Real certificates differ in how they compound and credit interest, so confirm the exact terms of your own deposit before relying on the figure.