CD Calculator (Certificate of Deposit)
What a CD or fixed-term deposit is worth at maturity, and the interest it earns.
Good to know. A CD pays more for leaving money alone. The hard part is leaving it alone.
Not financial advice. Uses only the numbers and rates you enter — no live data.
How it works
In plain words
The APY already includes compounding, so grow the deposit by the APY for each year of the term, and by a fraction of it for part of a year.
The formula
value = deposit × (1 + APY)^(months ÷ 12) interest = value − deposit
Worked example
10,000 in a 2-year CD at 4.5% APY: 10,000 × 1.045² = 10,920.25, so 920.25 of interest.
Sources
- Brealey, Myers and Allen, Principles of Corporate Finance, chapter 2 The standard formulas for loan payments, compounding and present value, the same as a spreadsheet’s PMT and FV.
- FDIC, Deposit Insurance Coverage up to $250,000 per depositor, per bank, per ownership category.
Sources checked September 30, 2026. 3 automated tests check its answers on every change.
About the CD calculator (certificate of deposit)
A certificate of deposit, or CD, pays a fixed rate for a fixed term, from a few months to five years or more, in return for leaving the money untouched. In the UK and elsewhere, the same thing is called a fixed-rate bond, term deposit or fixed deposit. The rate is usually higher than an easy-access savings account, and you know from day one exactly what you will get.
Enter the APY, the rate the bank advertises. It already includes compounding, so the result is the same whether interest is added daily or monthly, as long as it stays in the account. If you have the interest paid out instead, you earn a little less, roughly the plain annual rate. The APR to APY calculator converts between the two.
Taking money out before the term ends usually costs a penalty, often a few months of interest. A CD ladder, with several CDs maturing a year apart, keeps some money available each year while earning longer-term rates.
In the US, CDs at FDIC-insured banks and NCUA-insured credit unions are protected up to $250,000 per depositor per bank. Interest is taxable each year, even on a multi-year CD where you receive it at the end, unless the CD is held in an IRA.
Questions people ask
How much will a CD earn?
The deposit times (1 + APY) for each year. 10,000 at 4.5% APY earns 450 in one year and 920.25 over two years.
Is a CD better than a savings account?
For money you won’t need until the term ends, it usually pays more and locks in the rate. For an emergency fund, easy access matters more.
What happens when a CD matures?
You get a grace period, usually 7 to 10 days, to withdraw or move the money. After that, many banks renew it for the same term at the current rate.