CD Calculator

This CD calculator (certificate of deposit calculator) shows the exact value of your CD at maturity from three inputs: deposit amount, APY, and term. Because banks advertise APY — annual percentage yield, which already includes compounding — the math is clean: your deposit grows at the APY rate for the length of the term, and the chart traces the balance month by month.

Worked example: a $10,000 CD at 4.25% APY for 12 months matures at exactly $10,425 — $425 of interest, guaranteed, which is the entire appeal of a CD: the rate is locked the day you open it, regardless of what the Federal Reserve does afterward. The same deposit in a 5-year CD at 3.80% APY grows to about $12,050.

CDs at FDIC-member banks are insured up to $250,000 per depositor, per bank, per ownership category — see the FDIC's deposit insurance rules (credit union certificates carry equivalent NCUA coverage). To compare a CD against leaving money in a variable-rate account, run the same numbers in the Interest Calculator. Splitting a deposit across several terms? The CD Ladder Calculator models the whole structure, and if you might need the money early, check the cost first in the CD Early Withdrawal Penalty Calculator.

A CD has two advertised numbers and they are not the same. The interest rate (nominal rate) is what the bank applies each compounding period; the APY is what you actually earn per year after compounding is included. A 4.17% rate compounded daily produces roughly a 4.26% APY — the more frequent the compounding, the wider the gap.

Formula the calculator applies:

Since APY already embeds the compounding frequency, entering the APY gives the exact maturity value whether your bank compounds daily, monthly, or quarterly. If your bank only quotes a nominal rate and compounding schedule, convert it: APY = (1 + rate ÷ n)n − 1, where n is compounds per year.

Monthly interest: on the $10,000 / 4.25% example, the first month earns about $34.75, growing slightly each month as interest compounds on interest. Some banks let you take interest as a monthly payout instead — note that disbursed interest doesn't compound, so a payout CD matures at the original principal and yields slightly less total than the compounded figure shown here.

Taxes: CD interest is ordinary taxable income in the year it's credited, not the year the CD matures — a 3-year CD generates a 1099-INT every year, per IRS Topic 403 on interest income. On multi-year CDs, budget for tax on interest you can't touch yet. CDs held inside an IRA defer this entirely.

Choosing a term is a bet on rate direction. When short-term rates exceed long-term rates (an inverted deposit curve, common when rate cuts are expected), a shorter CD pays more now but exposes you to reinvesting at lower rates later; a longer CD locks today's rate through the cuts. If you can't decide, that's precisely the problem a CD ladder solves — you hold every term at once.

When a CD beats a high-yield savings account: HYSA rates float and follow the Fed down; CD rates are contractual. If you won't need the money before maturity and CD rates match or beat your HYSA, the CD wins the moment rates fall. The reverse — needing flexibility, or a HYSA paying meaningfully more — favors staying liquid. Run both in the Interest Calculator to see the dollar gap over your horizon.