CD Calculator
Calculate how much your certificate of deposit will earn. See your ending balance, total interest, and year-by-year growth for any CD term and compounding frequency.
CD Details
Amount you are depositing into the CD.
Most online banks compound daily. Check your CD disclosure to confirm.
Quick Tips
- Always compare APYs — not nominal rates — when shopping CD rates.
- Daily compounding earns slightly more than monthly or quarterly at the same APY.
- Consider a CD ladder to maintain liquidity while capturing longer-term rates.
CD Maturity Results
Initial Deposit
$10,000.00
Interest Earned
+$512.67
Effective APY
5.127%
Early Withdrawal Estimate
Penalty estimate based on typical bank policies. Your actual penalty depends on your CD agreement.
Year-by-Year Growth
| Year | Interest This Year | Total Interest | Balance |
|---|---|---|---|
| 1 | $512.67 | $512.67 | $10,512.67 |
Term Comparison at 5.00% APY
| Term | Interest Earned | Ending Balance |
|---|---|---|
| 3 mo | $125.78 | $10,125.78 |
| 6 mo | $253.13 | $10,253.13 |
| 1 yr | $512.67 | $10,512.67 |
| 2 yr | $1,051.63 | $11,051.63 |
| 5 yr | $2,840.03 | $12,840.03 |
Educational Estimate
Results are based on the APY and compounding frequency you entered. Actual returns depend on your bank's specific terms. Early withdrawal penalties vary. Not financial advice — confirm details with your bank before opening a CD.
What Is a CD (Certificate of Deposit)?
A certificate of deposit (CD) is a time-deposit savings product offered by banks and credit unions. You agree to keep your money on deposit for a fixed term — typically ranging from three months to five years — in exchange for a guaranteed interest rate that is usually higher than a standard savings account. At maturity, the bank returns your full principal plus all accumulated interest. Because the rate is locked in at the time you open the account, CDs are predictable, low-risk investments that are particularly attractive when interest rates are high.
CDs are federally insured by the FDIC (for banks) or NCUA (for credit unions) up to $250,000 per depositor per institution, making them among the safest places to store money. Unlike savings accounts, which allow ongoing deposits and withdrawals, CDs require you to commit a lump sum for the full term. Withdrawing early typically triggers a penalty — usually measured in days of interest forfeited — which can erase a significant portion of your earnings on shorter-term CDs.
CDs come in several varieties. Traditional CDs have fixed rates and penalties. No-penalty CDs allow early withdrawal without a fee but typically offer slightly lower rates. Bump-up or step-rate CDs let you request a rate increase once during the term if rates rise. Brokered CDs are sold through investment brokerages rather than directly by banks. Jumbo CDs require minimum deposits — often $100,000 — and historically offered premium rates, though today's online banks often match or exceed jumbo rates on standard CDs.
How to Calculate CD Interest
CD interest is calculated using the compound interest formula, which accounts for the fact that interest earned in each compounding period is added to the principal, and subsequent interest is earned on that larger balance. There are three key variables that determine how much your CD earns: the interest rate (APY), the term length, and the compounding frequency.
The process is straightforward. First, identify your principal — the amount you are depositing. Second, note the APY (Annual Percentage Yield) quoted by the bank. Third, determine the compounding frequency and term. Then apply the compound interest formula to find your ending balance. Subtracting the original principal from the ending balance gives you the total interest earned.
To calculate manually: convert the APY to a decimal (divide by 100), divide by the number of compounding periods per year, add 1, raise to the power of total compounding periods, and multiply by your principal. This calculator handles all of this automatically and instantly updates whenever you change any input.
CD Interest Formula & Assumptions
Compound Interest Formula
A = P × (1 + r ÷ n)^(n × t)
The APY (Annual Percentage Yield) is related to the nominal rate by the formula: APY = (1 + r/n)^n − 1. When a bank quotes an APY, the compounding effect is already baked in, so you can use APY directly as the nominal rate with annual compounding (n=1) and get the same result. Most CD disclosures quote APY as required by the Truth in Savings Act — this calculator accepts APY directly, which is the most common use case.
Assumptions used in this calculator: no additional deposits during the CD term (fixed, single-premium CD); interest compounds continuously within each period; the rate remains constant throughout the term; early withdrawal penalty is estimated at the industry-standard days-of-interest forfeiture and may differ from your specific bank agreement.
Worked Examples
Example 1: $10,000 at 5.00% APY for 6 Months (Daily Compounding)
A = $10,000 × (1 + 0.05/365)^(365 × 0.5) = $10,252.25
Interest earned: $252.25. Effective APY: 5.116%. Early withdrawal (90-day penalty): would forfeit ~$123, leaving ~$10,129.
Example 2: $25,000 at 4.75% APY for 1 Year (Monthly Compounding)
A = $25,000 × (1 + 0.0475/12)^(12 × 1) = $26,212.80
Interest earned: $1,212.80. This is a popular CD term — many banks compete aggressively for 12-month deposits, often offering their highest available rates.
Example 3: $50,000 at 4.00% APY for 5 Years (Daily Compounding)
A = $50,000 × (1 + 0.04/365)^(365 × 5) = $60,998.11
Interest earned: $10,998.11. The 5-year CD earns nearly $11,000 more than the original deposit through the power of compounding. Year 5 earns significantly more interest than Year 1 because the compounding base is larger.
CD vs. Other Savings Options
Compare CDs against other common savings vehicles to find the right fit for your timeline and liquidity needs.
| Feature | CD | High-Yield Savings | Money Market | Treasury Bills |
|---|---|---|---|---|
| Rate Type | Fixed | Variable | Variable | Fixed at auction |
| Liquidity | Low (penalty) | High | High | Medium (tradeable) |
| FDIC/NCUA Insured | Yes | Yes | Yes | Backed by US Gov |
| State Tax on Interest | Yes | Yes | Yes | No (exempt) |
| Best For | Locked savings, rate certainty | Emergency fund | Checking alternative | State-tax-heavy investors |
When to Use This CD Calculator
- Shopping for a CD: Enter the APY and term from different banks to compare projected returns side by side before opening an account.
- Planning a CD ladder: Use the term comparison table to see how much different terms will earn at the same rate, helping you decide how to split your deposit across multiple CDs.
- Evaluating early withdrawal: Check whether your interest earned so far exceeds the estimated penalty before deciding to break a CD early.
- Retirement planning: Model how a large CD deposit could grow over 3–5 years as a low-risk complement to a stock or bond portfolio.
- Education savings: Project how much a short-term CD will be worth when tuition is due in 6–24 months.
Tips for Accurate Results
- Use APY, not nominal rate. Banks advertise APY by law. Entering APY into this calculator gives you the correct ending balance without needing to adjust for compounding frequency.
- Check your bank's compounding frequency. Online banks typically compound daily; traditional banks often compound monthly or quarterly. Select the correct option to match your actual account terms.
- Account for taxes. CD interest is taxable income. If you are in the 22% federal bracket, your after-tax return on a 5% APY CD is approximately 3.9%. Factor this into comparisons with tax-advantaged investments.
- Consider state tax exemption on Treasuries. If you live in a high-income-tax state like California or New York, Treasury bills (exempt from state tax) may yield more after-tax than a same-rate CD.
- Model the penalty before breaking a CD early. The early withdrawal estimate in this calculator shows a reasonable approximation — but your actual penalty is stated in your CD agreement. Call your bank for the exact figure.
Frequently Asked Questions
About This Calculator
Free CD calculator. Enter your deposit, APY, and term to instantly see your ending balance, total interest earned, and year-by-year growth. Works for any CD term.
Frequently Asked Questions
What is a CD (Certificate of Deposit) and how does it work?
A certificate of deposit (CD) is a savings product offered by banks and credit unions that pays a fixed interest rate for a set period of time. You deposit a lump sum, agree not to withdraw it for the term, and the bank pays you interest — typically compounded daily or monthly. At maturity, you receive your original deposit plus all accumulated interest. CDs are FDIC-insured up to $250,000 per depositor per institution, making them one of the safest savings vehicles available.
What is APY and how is it different from the interest rate?
APY (Annual Percentage Yield) accounts for the effect of compounding, while the nominal interest rate does not. For example, a 5% nominal rate compounded monthly has an APY of approximately 5.12%, because each month's interest is added to the principal before the next month's interest is calculated. Banks are required by the Truth in Savings Act to disclose APY, so when comparing CDs, always compare APYs rather than nominal rates.
What happens if I withdraw from a CD early?
Most CDs charge an early withdrawal penalty if you take out your money before the maturity date. The penalty is typically expressed as a number of days of interest — for example, 90 days of interest for CDs under 1 year, 150 days for 1–3 year CDs, and 180 days for CDs over 3 years. The exact penalty varies by bank and CD type.
How often does CD interest compound?
Compounding frequency varies by bank and product. Many online banks compound daily, which maximizes your yield. Traditional banks more commonly compound monthly or quarterly. The difference matters more at higher balances and longer terms. Always check the account disclosure for compounding frequency.
Should I ladder my CDs instead of putting everything in one?
CD laddering means spreading your deposit across CDs with different maturity dates — for example, one each at 3 months, 6 months, 1 year, 2 years, and 5 years. As each CD matures, you reinvest at the longest term available. This strategy gives you liquidity every few months while still capturing higher long-term rates.
Are CD interest earnings taxable?
Yes. Interest earned on a CD is taxable as ordinary income in the year it is credited to your account, even if you do not withdraw it. For CDs longer than one year, you typically owe taxes on the interest each year as it accrues. Your bank will send you a Form 1099-INT each year reporting the interest.
What is a jumbo CD and is the rate always better?
A jumbo CD requires a minimum deposit — usually $100,000, though some institutions set the threshold at $25,000 or $50,000. Jumbo CDs traditionally offered higher rates than standard CDs, but in the current high-rate environment, many online banks offer rates on standard CDs that are competitive with or even exceed jumbo rates at traditional banks.
Alex specializes in personal finance modeling with experience in investment analysis and tax optimization. He ensures every financial calculator follows current IRS guidelines and industry-standard formulas.
- CFA Level II Candidate
- B.S. in Finance, University of Michigan
- 8 years in financial planning tools