Free CD Calculator

Your CD at Maturity

The results card updates as you type. Because a CD pays a fixed rate for a fixed period, these are not really projections in the way a stock-market estimate is — they are arithmetic on terms the bank has already committed to.

Below those sits the penalty line. Fill in the penalty your bank charges and a hypothetical withdrawal month, and it converts the bank's "months of interest" wording into a dollar figure — along with what you would actually walk away with.

Open View Full Breakdown for the rate applied, the term in months, the interest and maturity value to the cent, and the net proceeds if you broke the CD early.

What Is a Certificate of Deposit?

A certificate of deposit is a deposit account with a deal attached: you agree to leave a lump sum untouched for a set period, and in return the bank fixes your interest rate for that whole period. At the end — maturity — you get your deposit back plus the interest.

Three features define it, and all three follow from that single trade:

• A fixed term. Terms commonly run from a few months to several years. You choose it when you open the account, and it does not change.
• A fixed rate. The APY is locked at opening. Market rates can move in either direction afterwards and your CD carries on paying what it promised.
• A penalty for leaving early. This is what makes the first two possible. Without it, the bank could not rely on holding your money for the term.

That is the whole product. A certificate of deposit calculator therefore has an easier job than most savings tools: there is no assumed rate of return to argue about, because the rate is contractual. What it does need to handle honestly is the penalty, which is where the real decision lies.

On safety, a CD is a deposit like any other. Accounts at an institution insured by the Federal Deposit Insurance Corporation, or at a credit union insured by the National Credit Union Administration, are protected up to the applicable limits if the institution fails. The cover applies per depositor, per institution and per ownership category, so a large balance at a single bank may not be fully covered. Confirm the institution is insured and check the current limits at the source.

What a CD is not: an investment in the market. The value cannot fall, but neither can it do more than the stated rate. That certainty is the point, and it is also the ceiling.

How CD Interest Is Calculated

Three inputs produce the maturity value, and it is worth being precise about the first one, because this is where a CD interest calculator can quietly go wrong.

APY, and why it is not APR

APY — annual percentage yield — is the rate you actually earn over a year with compounding already included. APR is a nominal rate that does not include it. Deposit products are quoted as APY, so a 5% APY must turn $1,000 into exactly $1,050 after one year. If a calculator takes that 5%, divides it by twelve and compounds monthly, it counts the compounding twice and reports $1,051.16 instead.

The gap looks trivial at one year on a small balance. It is not trivial on a five-year CD for a large deposit, and it is simply wrong either way. This page applies your APY as the annual yield it is: maturity value is the deposit multiplied by (1 + APY) raised to the number of years.

Compounding frequency

Banks compound CD interest daily, monthly or quarterly depending on the product, and you will sometimes see both an interest rate and an APY quoted. The APY is the one that already reflects whichever schedule applies. That is precisely why it exists and why institutions are required to disclose it — it makes two offers directly comparable regardless of how each one compounds.

So you do not need to know the compounding frequency to use this calculator. Enter the APY and the arithmetic is settled.

Term length

The term decides how many times the yield is applied. Interest compounds, so the growth curve bends upward slightly over longer terms rather than running in a straight line — the table further down makes that visible.

Longer terms often carry higher rates, though not always; the relationship between term and rate shifts with market conditions and sometimes inverts. Compare the actual APY on offer for each term rather than assuming longer is better paid.

Early Withdrawal Penalties

This is the part of a CD people most often misjudge, and the reason this page includes an early withdrawal penalty calculator rather than only a maturity figure.

Take money out before the term ends and the bank charges a penalty. It is almost always expressed as a set number of months of interest rather than a flat fee or a percentage of your balance. The number of months is chosen by the institution, written into the account agreement you sign, and is typically larger for longer terms.

We do not state how many months, because it is not ours to state — it varies by bank and by product. Read your agreement, find the figure, and enter it above.

The mechanism is worth understanding before you open a CD rather than after:

• The penalty is based on your deposit and rate, not on how long you actually held the CD. Withdrawing one month in and eleven months in can cost exactly the same.
• Early in the term is the expensive time to break it, because you have earned least. Later, the interest already accrued absorbs the penalty.
• Some institutions apply different penalties to different terms, so a penalty you saw on a one-year CD may not be the one on a five-year CD at the same bank.
• Terms can differ in other ways too — whether interest is credited to the CD or paid out, and whether the CD renews automatically at maturity if you do nothing.

Use the two optional fields above to test it. Enter the penalty your bank charges, then try different withdrawal months and watch the net figure. Finding the point at which breaking the CD stops costing you principal is a five-second exercise that tells you how much flexibility you are actually giving up.

CD vs High-Yield Savings

These two products answer the same question — where should cash sit? — with opposite priorities. Neither is better in the abstract; the right one depends on when you will need the money.

Read that table as a single trade: the CD pays you for giving up access, and the savings account pays you less for keeping it. Whether that is a good deal depends entirely on whether you will actually need the money during the term.

Some practical ways people resolve it. An emergency fund belongs in easy-access savings, full stop — the one moment you need it is the one moment a penalty would bite. Money with a date attached, such as a tax bill due in a year or a deposit for a purchase already scheduled, suits a CD whose term ends before that date. And a common middle path is to split: enough in savings to cover the unexpected, the rest locked in for a better rate.

Our savings calculator handles the variable-rate side, including regular monthly deposits, which a CD does not usually accept after opening. Running the same money through both pages is the quickest way to see what the lock-up is buying you. For the underlying mechanics of compounding, the compound interest calculator goes further.

One more comparison worth making is against rising prices. A fixed rate guarantees the number of dollars you will hold at maturity; it guarantees nothing about what those dollars will buy. If prices rise faster than your APY over the term, the balance grows while its purchasing power shrinks — and unlike a savings account, you cannot move the money somewhere better without paying the penalty.

Your CD's Value Through the Term

The maturity figure is the headline, but the path matters when you are weighing up the penalty. This table shows what the CD is worth at points along the way.

The interest column is the one to read against your penalty. Find the row where interest earned first exceeds the penalty your bank charges, and you have found the point from which breaking the CD would no longer cost you any of your original deposit. Before that row, it would.

Note that these intermediate values are what the CD has accrued, not what you could walk away with. Taking the money at any of those points means the penalty comes off first — which is exactly what the penalty line in the results card works out for you.

How to Use This CD Calculator

1. Enter your deposit. The lump sum going into the CD. Most CDs take a single deposit at opening and do not accept additions later.
2. Enter the APY. Take it from the offer you are actually looking at. If a bank quotes both an interest rate and an APY, use the APY — it already accounts for compounding.
3. Choose the term. This is how long the money is locked away, and it should end before the date you expect to need the money.
4. Add the early withdrawal penalty from the account agreement, expressed as months of interest. Optional, but it is the figure that tells you what the lock-up really costs.
5. Try a withdrawal month. Pick a point part-way through the term and read the net figure. If it is below your deposit, that is the penalty eating into principal.
6. Compare against easy-access savings. Run the same deposit through the savings calculator and see what the difference in rate is actually worth to you.

A useful habit: before opening any CD, test the worst realistic case rather than the expected one. You are not trying to predict whether you will break the CD — you are checking that you could survive it if you had to.

Treat the output as a planning estimate. It assumes the CD runs at the APY you enter, that interest stays in the account rather than being paid out, that the CD is not renewed automatically at maturity, and it deducts no tax. Nothing you enter is stored or sent anywhere.

Our Methodology

Maturity value is the deposit multiplied by (1 + APY) raised to the term in years. Because the APY you enter is an annual yield that already contains the compounding, no further compounding is applied — that is the single most important decision in the engine. A 5% APY therefore turns $1,000 into exactly $1,050 after one year, where dividing the APY by twelve and compounding monthly would wrongly report $1,051.16.

The early withdrawal penalty is computed as the interest the deposit earns over the penalty period at the same APY: deposit × ((1 + APY)^{months ÷ 12} − 1). This is what "N months of interest" actually means, and because interest compounds it is slightly less than a flat pro-rata slice of a year's interest. Net proceeds are the deposit plus interest accrued by the withdrawal date, minus that penalty — and the page states plainly when the result falls below the original deposit.

Before publication the engine was cross-checked against an independently written month-by-month simulation across six scenarios with no disagreement. The penalty was verified to scale linearly with the deposit, to equal exactly one year's interest at twelve months, and to grow with the penalty period; the critical case — a penalty exceeding the interest earned, producing net proceeds below the deposit — was confirmed to be reported correctly. Zero-rate, zero-term and at-maturity edge cases were each tested, and all currency is rounded to cents before display so float artifacts never reach the page.

No rate and no penalty period appear anywhere on this page as a suggestion, default or example of what you might be offered. The 5% figure above exists only to demonstrate the APY arithmetic; both input fields ship empty.

Related Calculators

These free tools cover the rest of the picture: