CD Calculator (Certificate of Deposit)

A certificate of deposit is a simple bargain with a bank: you hand over a deposit, the bank hands back a fixed APY for a fixed term, and neither side can renegotiate. The rate is locked even if the Fed slashes rates the month after you sign - which is the entire appeal versus a savings account whose APY drifts down with the market. The price of that lock is access: pull the money early and a penalty takes a bite of your interest. This calculator shows the full arc - maturity value, total interest, and how the balance grows at checkpoints along the term.

The math is unusually honest because of how CDs are quoted. Banks advertise APY - annual percentage yield - which by law already includes the effect of monthly or daily compounding. So the calculator grows your deposit by a factor of (1 + APY) per year and nothing else: a 12-month CD at 4.25% turns $10,000 into $10,425.00, and the same APY held for 60 months compounds to $12,313.47 - $2,313.47 of interest on a deposit that never once surprised you.

Early withdrawal is where CDs bite. Break one open and the bank typically forfeits a set amount of interest - often around 3 months on a 1-year CD and up to 12 months on a 5-year CD (typical; each bank sets its own schedule). If the penalty exceeds the interest already credited, the difference comes out of principal. No-penalty CDs exist but pay a lower APY for the courtesy. Before locking a term, match it to when you will actually need the money.

Safety is the other half of the pitch. Bank CDs are FDIC insured up to $250,000 per depositor, per bank, per ownership category - credit unions offer the identical limit through the NCUA. Held to maturity, there is no market risk, no volatility, no scenario where the number comes out lower. The one enemy a CD cannot escape is inflation: a 4.25% APY in a 3% inflation world is roughly a 1.2% real return, which is fine for near-term money and a poor long-term engine.

Two follow-ups worth doing after you get your number. First, taxes: CD interest is ordinary income in the year it is credited - our federal tax brackets page converts the APY into an after-tax yield. Second, structure: the ladder comparison above shows that splitting the same deposit into 1-year tranches costs nothing at equal APYs - and for open-ended growth with contributions, the investment calculator picks up where a fixed term ends.