Skip to main content
CalcVerdict

CD Calculator

Find what a certificate of deposit is worth at maturity: total interest, true APY, and the early-withdrawal penalty if you cash out before the term ends.

FinancialWorks without JavaScriptReviewed 2026-08-26

Inputs

Your numbers

The lump sum you open the CD with. Nothing more can be added before maturity.

The nominal rate the bank quotes. The APY is reported with your result.

How long the deposit is locked up, in months (12 for a 1-year CD, 60 for a 5-year CD).

Months of interest your bank forfeits if you cash out before maturity, from your CD disclosure. Leave at 0 if you plan to hold to maturity.

Try an example

Result

Enter your values and press Calculate to see the result here.

Formulas verified against the primary sources cited below. Last checked 2026-08-26.

Built and maintained by Eddy Bo, founder of CalcVerdict.

How does this calculator work?

A certificate of deposit is a single lump sum locked with a bank for a fixed term at a fixed rate, with nothing added and nothing withdrawn before maturity. That single fact is what makes its maths simpler than a savings account with a contribution schedule: the balance grows by one closed-form factor rather than a period-by-period ledger. The SEC’s Investor.gov compound interest calculator states it as A = P(1 + r/n)^(nt), where P is the deposit, r the nominal annual rate the bank quotes, n the number of times a year that rate compounds, and t the term in years. This calculator takes the term in months, so a 6-month CD compounding daily produces a fractional exponent (n·t = 182.5) rather than a whole number — the formula and the arithmetic behind it (`powFrac`) handle that directly, the same way a fractional day count is handled when a bank states its own APY under Regulation DD. Speaking of which: the nominal rate a CD advertises is not what it pays over a year, because it does not reflect compounding. 12 CFR Part 1030 (Regulation DD), Appendix A, Part I gives the annual percentage yield as APY = 100[(1 + r/n)^n − 1] — a 4.5% CD compounded daily actually yields 4.60%, and that APY figure, not the nominal rate, is the one worth comparing across banks. The other half of the picture is what happens if you need the money before the term ends. Regulation DD (12 CFR § 1030.4(b)(4)) requires a bank to disclose its early-withdrawal penalty up front but does not standardise the amount; the structure nearly every issuer uses forfeits a stated number of months of interest, computed as simple interest: Penalty = P × (r/100) × (m/12) for m forfeited months. This calculator reports that penalty uncapped rather than protecting principal by assumption, because on a CD cashed out shortly after opening the penalty can genuinely exceed the interest earned so far — a real risk your specific disclosure may or may not carry, and one worth seeing rather than hiding. The deposit itself is a separate question from the rate: at an FDIC-member bank or NCUA-insured credit union it is insured up to $250,000 per depositor, per ownership category, per institution, regardless of how this calculator’s numbers come out. If you want to model regular contributions instead of a single lump sum, or compare compounding frequencies on an ordinary savings account, the compound interest calculator covers that; for a lump sum under simple interest, daily compounding, or after-tax comparisons, see the interest calculator.

What questions do people ask about this calculator?

What is a CD?

A certificate of deposit is a time deposit: you lock a lump sum with a bank or credit union for a fixed term at a fixed rate, and in exchange for giving up access to the money you usually earn more than a standard savings account pays. Unlike a savings account, nothing is normally added or withdrawn until the term ends at maturity.

What is the difference between the interest rate and the APY?

The nominal rate is quoted per year but credited more often; the annual percentage yield is what a full year of that compounding actually pays. Regulation DD, 12 CFR Part 1030 Appendix A, states the general rule as APY = 100[(1 + r/n)^n − 1] for a rate compounded n times a year. A 4.5% CD compounded daily works out to a 4.60% APY — the number worth comparing across banks, since the nominal rate alone is not.

How is the maturity value calculated?

A CD is a single deposit with no additions before maturity, so its value grows by one closed-form factor: A = P(1 + r/n)^(nt), where P is the deposit, r the nominal annual rate, n the compounding periods per year, and t the term in years. The SEC’s Investor.gov compound interest calculator states the identical formula for a lump sum.

What happens if I withdraw before the CD matures?

Almost every CD carries an early-withdrawal penalty, and Regulation DD (12 CFR § 1030.4(b)(4)) requires the bank to disclose it up front, but it does not standardise the amount. The most common structure forfeits a stated number of months of interest — this calculator models exactly that. On a short-term CD cashed out almost immediately, that penalty can exceed the interest you have actually earned, which means you can get back less than you deposited. Read your specific CD’s disclosure; do not assume principal is protected.

Does compounding frequency matter much on a CD?

Less than the rate or the term, but it is not nothing. $25,000 at 3% for five years grows to $28,981.85 compounded annually and $29,045.68 compounded daily — about $64 apart. Pick the better rate first; frequency is a smaller, secondary lever.

Is CD interest taxable?

Yes. Interest a CD earns is generally taxable income in the year it is credited, even if the CD has not yet matured and you have not touched the money, and even inside a multi-year CD that compounds without paying out. This calculator reports the pre-tax nominal figures; check with a tax professional about your specific situation.

Are CDs FDIC-insured?

CDs at FDIC-member banks are insured up to $250,000 per depositor, per ownership category, per bank — the same standard limit that covers checking and savings accounts. Credit union CDs carry equivalent NCUA coverage. That insurance is separate from anything this calculator computes; it protects the deposit, not the advertised rate.

Sources