CD Calculator
United States Uses U.S. IRS retirement-account and federal deposit rules. Figures are in U.S. dollars.
CD calculator: what a certificate of deposit earns from the advertised APY, interest after tax, the real return, and the cost of withdrawing early.
Educational estimate only. Not a lending decision. Your numbers stay in this browser.
Results
How to read this: the verdict describes how much room your numbers leave, not a decision or an offer. Change any input to see how much the result moves.
Investing and retirement guides
These guides explain compounding, contribution projections, retirement targets, inflation, and real returns.
- Compound interest explained
- Investment return with contributions
- Retirement savings target
- Inflation and real returns
For all guide topics, open Guides. For source and estimate boundaries, read Calculation Methodology and Sources and Assumptions.
Assumptions and formula
Banks must quote the annual percentage yield (APY), which already includes compounding: APY = (1 + r/n)ⁿ − 1 for an interest rate r compounded n times a year (Regulation DD). The calculator converts the APY to the rate for your compounding and grows the deposit month by month to maturity, so a one-year CD always grows by exactly its APY.
Tax: CD interest is ordinary income in the year it is credited, even when it stays in the CD; the tax uses the rate you enter. The today’s-dollars figure deflates the deposit plus after-tax interest by inflation over the term. The early-withdrawal penalty is months of interest on the deposit at the CD’s interest rate, the usual form; a long penalty on a short CD can take back some of the deposit.
Worked example
$10,000 in a 12-month CD at a 4.50% APY matures at $10,450. At a 22% tax rate you keep $351 of the interest, and with 3% inflation the result is worth $10,049.51 in today’s dollars, a real return of about 0.5%. Withdrawing at month 6 with a three-month penalty returns about $10,112.
Frequently asked questions
What does $10,000 in a 1-year CD at 4.5% earn?
$450 at a 4.50% APY, for $10,450 at maturity. At a 22% tax rate you keep $351, and with 3% inflation the real return is about 0.5%.
How much will a CD earn?
Deposit × (1 + APY) for a one-year CD, whatever the compounding, because the APY already includes it. $10,000 in a 12-month CD at a 4.50% APY matures at $10,450. For longer terms the APY compounds each year: five years at 4% turns $10,000 into $12,166.53.
Should I enter the APY or the interest rate?
The APY, which is the figure banks must advertise. The interest rate is lower because it does not include compounding: a 4.50% APY compounded daily is a 4.40% interest rate. Typing a 4.50% APY into a calculator that expects the interest rate and compounds it monthly overstates the yield as 4.59%. This calculator takes either and shows the other.
How much is the penalty for cashing a CD early?
It depends on the bank and the term, commonly three to twelve months of interest. Breaking a $10,000 12-month CD at a 4.50% APY after six months with a three-month penalty returns about $10,112: six months of interest less three months as the penalty. On a short CD, a long penalty can take back some of your deposit.
Is CD interest taxable?
Yes, as ordinary income in the year it is credited, even if you leave it in the CD until maturity. The bank reports it on Form 1099-INT. At a 22% rate, $450 of interest leaves you $351.
Does a CD beat inflation?
Only by a little, after tax. $10,000 at 4.50% for a year, taxed at 22%, with 3% inflation, is worth $10,049.51 in today’s dollars: a real return of about 0.5%. The calculator shows the real return for your rate, term and tax rate.
Is this a CD rate calculator or a CD return calculator?
Both. As a CD rate calculator it converts between the APY and the interest rate for any compounding; as a CD return calculator, or CD deposit calculator, it shows the maturity value, the interest, the tax and the real return of a certificate of deposit account. Use it as a CD account calculator or certificate of deposit rates calculator: an online CD calculator for any bank’s CD.
Is this a CD interest calculator?
Yes: a CD interest calculator and certificate of deposit interest calculator that shows the CD payout at maturity, your CD earnings after tax, and what an early withdrawal penalty would cost.
Sources
Sources reviewed 3 October 2026: checked against their current editions on that date.
- Regulation DD (Truth in Savings), 12 CFR part 1030, Appendix A: the annual percentage yield formula, and the requirement to state the APY in advertisements.
- IRS Publication 550, Investment Income and Expenses: interest on certificates of deposit is taxable in the year it is credited.
- FDIC, deposit insurance: $250,000 per depositor, per insured bank, for each account ownership category.
This page is an educational estimate, not personal financial or tax advice. Eligibility and individual circumstances can change the result.