United States · Savings
CD calculator.
Enter a deposit, rate and term to see interest earned, the ending balance, tax on the interest and what an early withdrawal would cost.
A CD earns deposit × ((1 + APY)years − 1). APY already includes compounding; if the bank quotes APR (interest rate) instead, the calculator converts it using the compounding schedule.
Your CD
Earnings
APY, APR and what the bank quotes
Under Regulation DD (Truth in Savings), banks must disclose the annual percentage yield, which is the effective annual return including compounding. The "interest rate" is lower than the APY whenever interest compounds more than once a year: a 4.00% rate compounded daily is a 4.08% APY. This tool lets you enter either. With an APY it grows the deposit by (1 + APY) raised to the number of years; with an interest rate it first converts to APY using the compounding schedule you pick.
Worked examples
A $10,000 12-month CD at 4.50% APY earns $450.00 and ends at $10,450.00. At a 24% combined tax rate, $108.00 goes to tax, leaving $342.00. A 3-month penalty would forfeit about $110.24 of interest. A $25,000 five-year CD at a 4.00% rate compounded daily has an APY of 4.0808% and ends at $30,534.73, earning $5,534.73 before tax.
Things that change the real return
- Taxes. CD interest is taxable 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 when it is $10 or more. State tax applies in most states.
- Early-withdrawal penalties. Breaking a CD early typically forfeits a set number of months of interest, and in some cases can cut into principal. The calculator estimates the penalty as that many months of interest.
- Insurance limit. FDIC and NCUA insurance covers $250,000 per depositor, per insured institution, per ownership category.
- Reinvestment risk. When a CD matures you roll into whatever rates are then available. A ladder of staggered maturities spreads that risk.
- Inflation. Compare the after-tax yield with expected inflation to see the real return.
What this tool does not cover
Interest paid out monthly rather than compounded in the CD, variable-rate and bump-up CDs, brokered CDs that trade on a secondary market and callable CDs that the issuer can redeem early.
Common mix-ups
Entering an interest rate in the APY box (APY already includes compounding); assuming interest is untaxed until maturity (it is taxed in the year credited); and treating an early-withdrawal penalty as a fixed dollar fee when it is usually months of interest.
Frequently asked questions
How is CD interest calculated?
Ending balance = deposit × (1 + APY)^(months / 12). Interest is the ending balance minus the deposit. If you only have the interest rate, convert it to APY with the compounding schedule first.
What is the difference between APY and interest rate?
The interest rate is the nominal rate. APY is the effective yearly return after compounding, so it is higher whenever interest compounds more than once a year.
Is CD interest taxable every year?
Yes. Interest is taxed in the year it is credited to the account, even if you cannot withdraw it without penalty. You get a Form 1099-INT from the bank.
What happens if I withdraw early?
The bank charges a penalty, often a number of months of interest, which can exceed what you have earned if you withdraw soon after opening the CD.
Are CDs insured?
CDs at FDIC-insured banks and NCUA-insured credit unions are insured up to $250,000 per depositor, per institution, per ownership category.
Sources
- eCFR, 12 CFR Part 1030 (Regulation DD, Truth in Savings) — how annual percentage yield is defined and calculated (retrieved 2026-11)
- FDIC, Deposit insurance — the $250,000 per depositor, per bank, per ownership category limit (retrieved 2026-11)
- IRS Tax Topic 403, Interest received — CD interest is taxable in the year it is credited, reported on Form 1099-INT (retrieved 2026-11)
Last updated November 8, 2026. Tax-law figures are for tax year 2026.
Estimate only
This is an educational calculation, not tax, legal or investment advice. Your plan, lender, employer or tax professional has the final numbers.