Certificate of Deposit Calculator
Work out what a certificate of deposit pays at the end of its term: put in the amount you are depositing, the rate from the disclosure and the number of months the money is locked up, and the maturity value, the interest and the effective yield come back as you type. It opens on a twelve month term and takes any term from a single month to fifty years. The rate you enter is the only rate in the answer, and the whole calculation happens in your browser.
Balance along the way
The balance at the end of each year, and at maturity. Interest is added each month and left in the certificate, which is what makes the yield higher than the rate.
| After | Balance | Interest so far |
|---|---|---|
| 1 year | 10,459.40 | 459.40 |
Worked examples
Three certificates worked through, each one loadable into the fields above. The figures are illustrations of the arithmetic, not rates on offer.
Common questions
- What term should I enter for a one-year CD?
- Twelve, which is how this page opens. The term field is a whole number of months, so an 18 month certificate is 18 and a five-year certificate is 60. Months are used rather than years because that is how certificates are sold: odd promotional terms such as 7, 9 or 13 months are ordinary, and a page that only accepted whole years could not price one.
- Should I enter the rate or the APY from the offer?
- Whichever the offer printed, and then say which it was with the toggle beside the field. If the bank advertises 4.5% APY compounded monthly, set the toggle to APY and the stated rate behind it, 4.409771%, is worked out and shown. If it advertises a 4.5% rate, leave the toggle on APR and the effective yield of 4.593983% is shown instead. Reading an advertised yield as a stated rate is what makes an estimate come out high: on $10,000 for a year, it adds $9.40 that the certificate does not pay.
- What is the difference between a CD and a savings account here?
- For the arithmetic, only the term. A certificate fixes the rate for a stated number of months, so the whole term can be computed in advance, which is what this page does. A savings account rate can move at any time, so the same calculation is a projection rather than a maturity value. Nothing on this page models a rate that changes partway through.
- Does it account for the early withdrawal penalty or tax?
- No, and it says so on the accuracy line. A penalty is a term of your contract, usually stated as a number of months of interest, and tax treatment depends on where you live and what kind of account holds the certificate. Both come off the disclosure, not off a calculator. The figure here is the gross interest the arithmetic produces.
- Can I see the balance part way through the term?
- Yes. Under the fields, the balance is listed at the end of each year of the term and again at maturity, so a 60 month certificate shows five rows and an 18 month one shows the twelfth month and the eighteenth. The last row is the maturity value itself rather than a second calculation of it, so the table and the headline can never disagree.
Exact compound interest arithmetic on the deposit, rate, term and compounding you enter. It cannot know your bank's early withdrawal penalty, fees or tax treatment, and it does not carry any rate of its own.