How is CD interest calculated?

CD interest is calculated using the compound interest formula: A = P(1 + r/n)^(nt), where P is the principal, r is the annual interest rate (APY), n is the number of compounding periods per year, and t is the time in years. For a CD with daily compounding at 4.5% APY on $10,000 for one year, you would earn approximately $460 in interest.

What is the difference between APY and APR on a CD?

APY (Annual Percentage Yield) accounts for compounding and represents the actual return you earn in a year. APR (Annual Percentage Rate) is the stated rate before compounding. For CDs, banks typically advertise APY, which already reflects the effect of compounding. A CD with 4.5% APR compounded daily has an APY slightly higher than 4.5%.

How does compounding frequency affect CD earnings?

More frequent compounding means slightly higher returns. With the same stated APY, daily compounding yields marginally more than monthly, which yields more than quarterly, which yields more than annual. The difference is small but adds up on larger deposits or longer terms. Many online banks offer daily compounding.

Are CDs FDIC insured?

Yes. CDs held at FDIC-member banks are insured up to $250,000 per depositor, per bank, per account ownership category. At credit unions, CDs are insured by the NCUA up to the same limit. Deposits exceeding $250,000 at a single institution are not insured and could be at risk if the bank fails.

CD Interest Calculator 2026

Q: Is CD interest taxable?

Yes, CD interest is taxable as ordinary income at the federal level in the year it is earned or credited, even if you don't withdraw it. You will receive a 1099-INT form from your bank. State taxes may also apply. Tax-advantaged accounts like IRA CDs defer taxation until withdrawal.

Enter CD Details

Initial Deposit $10,000

$500 $250,000

APY / Interest Rate 4.50%

0.50% 6.00%

CD Term

Compounding Frequency

Daily

Monthly

Quarterly

Annually

Results at Maturity

Total Value

$10,460

Interest Earned

$460

Effective APY

4.50%

After-Tax Interest

$359

Tax Estimate (22%)
$101

Maturity Date
May 2027

FDIC Protected — deposit is within $250,000 limit

Year-by-Year Interest Breakdown

Year	Starting Balance	Interest Earned	Ending Balance

How CD Interest Works

A certificate of deposit (CD) is a time-deposit savings product offered by banks and credit unions. You agree to leave your money deposited for a fixed term in exchange for a guaranteed interest rate — typically higher than a standard savings account.

CD interest compounds over time using the formula: A = P(1 + r/n)^(nt), where P is principal, r is the annual rate, n is compounding periods per year, and t is time in years.

Tax note: The 22% federal bracket estimate shown is illustrative only. Your actual tax rate depends on your total income, filing status, and state tax laws. Consult a tax professional.

Information is for educational purposes only and does not constitute financial advice. Consult a qualified financial advisor.

Frequently Asked Questions

CD interest uses the compound interest formula A = P(1 + r/n)^(nt). For a $10,000 CD at 4.5% APY compounded daily for 1 year, you earn approximately $460 in interest. More frequent compounding results in slightly higher earnings.

APY (Annual Percentage Yield) accounts for compounding and represents your true annual return. APR is the base rate before compounding. Banks typically advertise APY for CDs. Daily compounding at 4.5% APR yields an APY of about 4.603%.

Yes. CD interest is taxed as ordinary income in the year it is credited, even if you don't withdraw it. You will receive a 1099-INT form. IRA CDs defer taxes until withdrawal. State taxes may also apply.

Yes, but the difference is usually small. Daily compounding earns slightly more than monthly, which earns more than annual. On a $100,000 5-year CD at 5%, the difference between daily and annual compounding is roughly $200–$300 total.

Yes. FDIC-member banks insure CDs up to $250,000 per depositor per bank per ownership category. Credit unions offer equivalent NCUA coverage. Deposits above this limit at a single institution are uninsured. Spreading funds across banks increases total coverage.

Current CD Rate Environment

1-Year CD (avg)4.40%

2-Year CD (avg)4.20%

5-Year CD (avg)4.00%

FDIC Limit$250,000

Source: FDIC National Deposit Rates, May 2026

CD Interest Calculator 2026

Enter CD Details

Results at Maturity

Year-by-Year Interest Breakdown

How CD Interest Works

Frequently Asked Questions

How is CD interest calculated?

What is the difference between APY and APR?

Is CD interest taxable?

Does compounding frequency matter?

Are CDs FDIC insured?

Current CD Rate Environment

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