CD Calculator
Calculate the maturity value and interest earned on a certificate of deposit.
Formula
About this calculator
A CD calculator shows exactly what a certificate of deposit will be worth when it matures. Because a CD locks in a fixed rate for a fixed term, the outcome is fully predictable — enter your deposit, the annual rate, the term length and how often interest compounds, and the tool returns your maturity value, the total interest earned and the effective annual yield.
The math is the standard compound interest formula: your principal multiplied by one plus the periodic rate, raised to the number of compounding periods. Compounding frequency matters more than many savers realise — a rate that compounds daily produces slightly more than the same rate compounding annually, because interest starts earning interest sooner. That difference is captured by the APY, the single figure that lets you compare CDs on an equal footing regardless of how they compound.
CDs trade flexibility for certainty. Unlike a regular savings account, your money is committed for the term, and withdrawing early usually triggers a penalty that can eat into or wipe out the interest. In return you typically get a higher, guaranteed rate — which makes CDs well suited to money you know you won't need until a specific date.
Every number here comes straight from your inputs, so the projection is exact for a CD held to maturity at the stated rate. Use the APY it reports to shop between offers, and remember that once the term ends many CDs roll over automatically unless you instruct otherwise.
Frequently asked questions
How is CD interest calculated?
Using compound interest: principal × (1 + rate/n)^(n × years), where n is the number of compounding periods per year. The maturity value minus your deposit is the interest earned.
What is APY?
Annual percentage yield is the effective yearly return once compounding is included. It's higher than the stated rate when interest compounds more than once a year, and it lets you compare CDs fairly.
Does compounding frequency change my return?
Yes, slightly. More frequent compounding — daily versus annually — earns a little more on the same nominal rate, because interest begins earning interest sooner. The APY reflects this.
What happens if I withdraw early?
Most CDs charge an early-withdrawal penalty, often several months of interest, which can reduce or erase your earnings. This calculator assumes you hold the CD to maturity.
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⚠️ Results assume the CD is held to maturity at the stated rate and are estimates, not financial advice. Early withdrawal penalties and rate changes at rollover are not included.