CD Calculator
Calculate the exact interest your certificate of deposit will earn at maturity. Enter your deposit amount, APY, and term length to see your total earnings, maturity value, and how early withdrawal penalties would affect your payout.
Annual Percentage Yield — already accounts for compounding
1–120 months
Initial Deposit
$10,000.00
Interest Earned
$450.00
Maturity Value
$10,450.00
Principal vs. Interest Breakdown
Early Withdrawal Penalty Estimate
If you withdraw your CD before maturity, your bank will typically charge a penalty expressed as a number of days of interest. Below are estimates based on common penalty tiers — actual terms vary by institution.
| Penalty Period | Penalty Amount | You Receive |
|---|---|---|
| 90-Day Penalty | −$110.96 | $10,339.04 |
| 180-Day Penalty | −$221.92 | $10,228.08 |
| 365-Day Penalty | −$450.00 | $10,000.00 |
Actual penalties vary by institution. Most banks will not reduce your payout below the original deposit.
Month-by-Month Breakdown
| Month | Starting Balance | Interest Earned | Ending Balance | Total Interest |
|---|---|---|---|---|
| 1 | $10,000.00 | $36.75 | $10,036.75 | $36.75 |
| 2 | $10,036.75 | $36.88 | $10,073.63 | $73.63 |
| 3 | $10,073.63 | $37.02 | $10,110.65 | $110.65 |
| 4 | $10,110.65 | $37.15 | $10,147.80 | $147.80 |
| 5 | $10,147.80 | $37.30 | $10,185.10 | $185.10 |
| 6 | $10,185.10 | $37.42 | $10,222.52 | $222.52 |
| 7 | $10,222.52 | $37.57 | $10,260.09 | $260.09 |
| 8 | $10,260.09 | $37.70 | $10,297.79 | $297.79 |
| 9 | $10,297.79 | $37.85 | $10,335.64 | $335.64 |
| 10 | $10,335.64 | $37.98 | $10,373.62 | $373.62 |
| 11 | $10,373.62 | $38.12 | $10,411.74 | $411.74 |
| 12 | $10,411.74 | $38.26 | $10,450.00 | $450.00 |
Results are estimates based on the values you enter and are for informational purposes only. They do not constitute financial or investment advice. CD rates, terms, and early withdrawal penalties vary by institution. Always verify with your bank and consult a qualified financial professional before making deposit decisions.
How to Use This CD Calculator
This calculator gives you a complete picture of your CD earnings before you open an account. Follow these steps:
- Enter your deposit amount — the lump sum you plan to deposit into the CD. This is your principal and will not change during the term.
- Enter the APY from your bank or comparison site — use the Annual Percentage Yield (APY) advertised for the CD. APY already accounts for compounding, so no additional adjustments are needed.
- Set the term using the quick-select presets or enter a custom number of months — choose from common terms (3 months to 5 years) or type any value between 1 and 120 months.
- Review your results — see your maturity value, total interest earned, and the month-by-month breakdown. The early withdrawal table shows estimated penalties if you need to access funds before maturity.
Use the results to compare CD offers from multiple banks. Even small differences in APY can meaningfully change earnings on larger deposits or longer terms.
CD Formulas & Reference
CD Maturity Formula
A = P × (1 + APY)^t- A = Maturity value
- P = Principal (initial deposit)
- APY = Annual percentage yield as a decimal
- t = Term in years
Example: $10,000 at 4.5% APY for 1 year → $10,450.00
Interest Earned
I = A − P- I = Total interest earned
- A = Maturity value
- P = Principal
Example: $10,450.00 − $10,000.00 = $450.00 interest earned
Term Comparison at 4.5% APY on $10,000
| Term | Maturity Value | Interest Earned |
|---|---|---|
| 3 months | $10,111.86 | $111.86 |
| 6 months | $10,224.68 | $224.68 |
| 12 months | $10,450.00 | $450.00 |
| 24 months | $10,920.25 | $920.25 |
| 36 months | $11,411.66 | $1,411.66 |
| 60 months | $12,461.82 | $2,461.82 |
APY (Annual Percentage Yield) already accounts for compounding frequency. This calculator uses APY directly for accurate results regardless of how frequently your bank compounds interest.
Frequently Asked Questions
A certificate of deposit (CD) is a savings product offered by banks and credit unions that pays a fixed interest rate in exchange for keeping your money on deposit for a set term. CDs typically offer higher interest rates than regular savings accounts because you agree not to withdraw the funds until maturity. They are FDIC insured up to $250,000 per depositor per institution, making them one of the safest savings vehicles available. The trade-off is limited liquidity — withdrawing early usually triggers a penalty.
CD interest is calculated using the formula A = P × (1 + APY)^t, where A is the maturity value, P is the principal deposit, APY is the annual percentage yield expressed as a decimal, and t is the term in years. Because banks advertise APY (which already incorporates compounding), you don't need to know the compounding frequency separately — the APY gives you the true annual growth rate. For example, $10,000 at 4.5% APY for 12 months equals $10,000 × 1.045^1 = $10,450.00.
APY (Annual Percentage Yield) is the effective annual rate of return that accounts for the effect of compounding within the year. APR (Annual Percentage Rate) is the nominal rate before compounding is applied. For a CD compounding monthly, the APR would be slightly lower than the APY. Banks advertise APY for CDs because it reflects the actual amount you'll earn — it's the more consumer-friendly figure. When comparing CD offers, always use APY to make an apples-to-apples comparison, regardless of how frequently each bank compounds interest.
If you withdraw funds from a CD before the maturity date, the bank will charge an early withdrawal penalty. This penalty is typically expressed as a certain number of days of interest — commonly 90 days, 180 days, or 365 days depending on the CD term and institution. For very short-term CDs or withdrawals made very early in the term, the penalty can sometimes eat into your original principal. Some banks offer 'no-penalty CDs' that allow early withdrawal without fees, though these products usually carry lower interest rates in exchange for the added flexibility.
The right CD term depends on when you'll need the money and your interest rate outlook. Longer-term CDs generally offer higher interest rates but lock up your funds for years. Shorter-term CDs offer more flexibility and let you reinvest sooner if rates rise. A popular strategy is CD laddering — opening multiple CDs with staggered maturity dates (e.g., 6-month, 12-month, 24-month, 36-month). This gives you periodic access to funds while still capturing higher rates on the longer-term portions, balancing yield with liquidity.
Yes. CDs at FDIC-member banks are insured up to $250,000 per depositor, per institution, per ownership category. CDs at NCUA-member credit unions are equally protected by the National Credit Union Administration up to the same limit. This makes CDs one of the safest places to hold savings. However, it's important to note that FDIC insurance protects against bank failure — it does not protect against inflation risk. If your CD rate is below the rate of inflation, the purchasing power of your savings may decline in real terms over the CD's term.
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