Certificate of Deposit Calculator
Estimate your CD interest and maturity value. Compare holding to maturity with withdrawing early, including penalties and a savings-account alternative.
Hold to maturity vs. withdraw early
| Measure | Hold to maturity | Early withdrawal |
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Total cash includes prior interest payouts plus the final CD settlement. Prior payouts are held without earning additional interest. Returns shown are for each scenario's holding period, not annualized APYs.
How this CD interest calculator works
APY and maturity value
For deposit P, decimal APY a, and holding period t in years, retained-interest value is P × (1+a)^t. We use t = months / 12. APY includes compounding, so we do not compound it a second time.
For n compounding periods per year, the equivalent nominal annual rate is r = n × ((1+a)^(1/n) − 1). This rate is used for the optional payout scenario and, unless overridden, the interest-based penalty. Frequency does not change maturity value when APY is held fixed and interest stays invested.
Interest paid out instead of reinvested
With payouts, each full compounding period pays P × r / n. Payouts before exit are held separately at 0%. A remaining partial period earns a proportional amount of simple interest, and any interest due exactly on the exit date belongs to the final settlement. Total interest is P × r × t; it does not earn interest itself. This generally reduces total cash compared with retaining interest.
The APY input is assumed to describe the CD with interest retained. Mandatory-payout CDs may quote yields differently; use your provider's contractual nominal rate and payout rules to check this estimate. This calculator does not model different payout and compounding schedules.
Early-withdrawal penalties
Days-of-interest penalty: P × penalty annual rate × days / 365. Months-of-interest penalty: P × penalty annual rate × months / 12. A fixed penalty uses your dollar amount. These are simple-interest estimates on the original principal, not compound-growth penalties. Enter the contract's nominal rate if it differs from the rate derived from APY.
If you explicitly choose an earned-interest cap, the penalty is limited to interest earned through withdrawal, including prior payouts. Otherwise, the full penalty applies and can reduce principal. The model rejects a penalty greater than the funds remaining in the CD; it does not assume an outside payment. No penalty is charged in the hold-to-maturity scenario.
Effective return and savings comparison
Total cash = prior payouts + CD balance before penalty at exit − penalty. Net gain = interest earned − penalty. The effective return after penalty is net gain / original deposit × 100% for the selected holding period. This is not an annualized return and should not be compared directly with an advertised APY.
The savings alternative keeps the same deposit invested for exactly the same period using your savings APY. Each column reports the CD's total cash minus that savings balance. The two columns have different timelines, so use each column's savings comparison rather than treating maturity and early exit as equal-duration investments.
Can an early-withdrawal penalty reduce principal?
Under the uncapped scenario, yes: if the penalty exceeds the interest earned, the combined cash returned is below your original deposit. Whether your provider permits early withdrawal and how the charge is calculated depend on your contract. The model does not infer special minimum penalties for immediate withdrawals.
Will this match my bank's statement exactly?
Not necessarily. We use equal months, accrued growth and full-precision calculations until display. Actual dates, leap years, daily-balance methods, posting dates, payout rounding and early-withdrawal terms can change the result.
Sources: CFPB guide to certificates of deposit and CFPB account-disclosure rules covering penalties and interest withdrawals. These explain the relevant concepts; the formulas above describe this calculator's assumptions.