Work out exactly what a certificate of deposit will be worth when it matures. Enter your deposit, the annual interest rate, the term and the compounding frequency, and this free CD interest calculator returns your total earnings, effective APY, estimated tax and early withdrawal penalty in one view.
Enter your deposit, rate, term and compounding to see your earnings.
Small differences in a CD rate add up over a long term. Put two advertised rates side by side and see exactly how much extra the higher rate delivers on the same deposit and the same term.
Rate B produces the higher maturity value on the same deposit and term.
A certificate of deposit is one of the most predictable places to park money. You hand the bank a fixed sum, agree to leave it alone for a set period, and the bank pays a stated rate of interest. The promise is simple. The arithmetic behind it is not always obvious, because compounding frequency, term length and the difference between nominal rate and APY all change the final number.
That is exactly what this interest rate for CD calculator solves. Instead of guessing, you enter four inputs and immediately see the total interest earned, the maturity value, the effective APY, and how much tax and an early withdrawal penalty could take away. The result is a realistic picture of what a certificate of deposit will actually deliver, not a headline rate that flatters the offer.
The tool is free, it runs entirely in your browser, and it works the same way on a phone, a tablet and a desktop. Nothing you type is stored on a server, and no account is needed to see your numbers.
Every field in this certificate of deposit calculator exists because it changes the outcome in a way that matters to a real saver. Here is what you can control and what the calculator returns.
Set any opening balance, from a few hundred dollars to a six figure sum. The principal drives every other figure in the model.
Enter the nominal annual rate the bank quotes. The calculator converts it into the effective APY so you can compare offers fairly.
Choose months or years, which covers a 6 month CD, a 12 month CD, a 5 year CD, or any custom term in between.
Switch between daily, monthly, quarterly, semi-annual and annual compounding to match the exact terms in your account agreement.
The gross interest figure shows how much the deposit generates before tax and before any penalty is applied.
Your closing balance at the end of the term, which is the number most savers actually want to know.
The annual percentage yield accounts for compounding, which makes it the correct figure when you compare two CD offers.
Enter your marginal tax rate to see how much of the interest is likely to disappear to income tax.
Model the cost of breaking the CD early by entering the penalty in months of interest.
Run two advertised rates on the same deposit and term to see the real gap in maturity value.
A compact table shows how the balance grows over the life of the CD, which is useful for longer terms.
Save your inputs and results as a plain text file so you can keep a record or share it with someone else.
The calculator is designed to be quick. Most people get a full answer in under a minute, and you can change any single field to see how sensitive the result is.
Tip: when two banks advertise similar rates, compare the APY rather than the nominal rate. Compounding differences of a few basis points are invisible in the headline number but visible in the maturity value.
The calculator is written for anyone who wants a straight answer about deposit growth. That includes people who have never opened a CD before and people who manage a portfolio of them.
The interest rate on a CD looks like a single number, but it interacts with three other variables that quietly decide your outcome. Understanding that interaction is what separates a good decision from an average one.
A 4.50 percent nominal rate compounded monthly produces a slightly higher effective APY than the same rate compounded annually. Over one year the gap is small. Over five years it compounds into a meaningful difference, which is why the APY field matters more than the advertised rate.
A 0.25 percent rate advantage is almost invisible on a 6 month CD. On a 5 year CD the same advantage produces a materially larger maturity value. Long terms reward patience but they also lock your money away, so the trade off has to be deliberate.
CD interest is generally taxed as ordinary income in the year it is credited, even if you leave it in the account. That means the interest you see on a statement is not the interest you keep. The optional tax field in this CD earnings calculator with taxes gives you a realistic net figure.
Most banks charge several months of interest if you close a CD before maturity. On a short term CD that penalty can wipe out most of the interest you earned. On a long term CD it can eat into the principal in extreme cases. Modelling the penalty before you commit is far cheaper than discovering it later.
No CD rate exists in isolation. The right question is never whether a rate is good, but whether it is better than the alternatives available to you today. A CD rate comparison calculator turns that question into a number.
A certificate of deposit is a straightforward product, and the maths behind it is not complicated once you can see it laid out. The difficulty is that banks quote rates in different ways, apply different compounding schedules and attach different penalties, which makes honest comparison hard.
This interest rate for CD calculator removes that friction. Enter your deposit, rate, term and compounding, and you get the maturity value, the total interest earned, the effective APY, and a realistic estimate of tax and penalty. Use it before you open a CD, use it when you are choosing between two offers, and use it again when you build a CD ladder. The numbers will tell you what the marketing material will not.
Short answers to the questions people ask most often about CD interest, maturity values and early withdrawal penalties.
Use the compound interest formula A = P x (1 + r / n) ^ (n x t). P is your deposit, r is the annual interest rate written as a decimal, n is the number of compounding periods per year, and t is the term in years. Subtract the original deposit from A and you have the interest earned.
The CD interest calculator on this page performs that calculation instantly and also converts the result into an effective APY so you can compare it with other deposit products.
Interest depends on four things: the deposit amount, the annual interest rate, the length of the term, and how often interest compounds. A 10,000 dollar deposit at 4.50 percent for 12 months with monthly compounding earns roughly 459 dollars before tax.
Change any one of those four inputs and the answer moves. The fastest way to see the effect is to type your own figures into the calculator above.
At a 4.00 percent annual rate for one year with monthly compounding, a 10,000 dollar CD matures at about 10,407 dollars. At 5.00 percent over five years it grows to roughly 12,833 dollars, assuming the rate stays fixed for the whole term.
Enter your own deposit and rate above for a precise maturity value, including any tax you expect to pay on the interest.
Compound interest adds earned interest back to the principal so the next period earns interest on a larger balance. Daily and monthly compounding produce slightly more than annual compounding at the same nominal rate, which is why the APY is always a little higher than the quoted rate.
The gap widens as the term lengthens, so compounding frequency matters most on multi-year CDs.
Compare APY rather than nominal rate, because APY already accounts for compounding. Then check the term, the minimum deposit, the early withdrawal penalty, and whether the rate is fixed or a promotional rate that resets.
The comparison card on this page shows the difference in maturity value between two rates on the same deposit and term, which is the clearest way to judge which offer is genuinely better.
In most countries CD interest is treated as ordinary income and is taxed in the year it is credited, even if you leave it in the account until maturity. The bank usually reports the interest on an annual tax statement.
The optional tax field in this calculator gives a rough estimate of the tax drag on your earnings. It is an estimate only and is not tax advice.
Most banks charge a penalty if you withdraw before maturity, usually expressed as a number of months of interest. A three month penalty on a 12 month CD means you forfeit roughly three months of earned interest.
Enter the penalty months in the calculator to see exactly how much of your interest disappears if you close the CD early.
A 12 month CD pays whatever annual rate the bank states for that term. If the bank advertises a 4.75 percent APY, a 10,000 dollar deposit matures at about 10,475 dollars.
Rates change frequently, so always confirm the current rate with the bank before you open the account, and check whether the rate is fixed for the full term or subject to change.