CD Calculator
Enter a deposit, term, and APY. See the maturity value before comparing offers or an early withdrawal.
Decision tools
Compare offers or test an early withdrawal
Compare up to three CDsSame deposit and term, different APYs
Early withdrawal vs. reinvestmentUse your bank's current balance and exact dollar penalty
One calculator, three CD decisions
The first form answers the basic question immediately: how much will this deposit be worth at maturity? The comparison uses one principal and one term for every APY, so its dollar spread is a like-for-like result. The early-withdrawal form compares both choices at the original remaining horizon.
APY formula and assumptions
This fixed year-fraction estimate uses maturity value = deposit × (1 + APY)term months ÷ 12. Regulation DD defines APY as an annualized yield that reflects interest and compounding. The model assumes a fixed APY, no deposits or withdrawals during the term, and that interest remains on deposit.
Actual bank calculations can differ because of product disclosures, daily accrual, required interest payouts, fees, taxes, or rounding. Verify the maturity value and penalty with the institution before moving money.
Early withdrawal without a hidden penalty guess
Enter the current balance and the exact dollar penalty your institution provides. ToolNeko subtracts that penalty, grows both choices for the same remaining month count, and calculates the new APY required to break even. A penalty may reduce principal; it only becomes invalid when it consumes the entire current balance.
Time zone and maturity-date note
The calculator uses a term in whole months and no server clock, so switching between US and Taiwan time zones does not change the dollar result. It does not replace the calendar maturity date in your deposit agreement; use the bank's date for notices, grace periods, or withdrawal instructions.
Frequently asked questions
Does this CD calculator use APY or an interest rate?
It uses annual percentage yield (APY). APY already reflects compounding over a year, so do not enter an APR or nominal interest rate.
How is CD maturity value estimated?
The estimate multiplies the deposit by (1 + APY) raised to the term in years. It assumes the APY stays fixed and all interest remains on deposit.
Can I compare CDs with different terms?
This page deliberately compares APYs using the same deposit and term. Comparing different maturity dates as if one were a winner would not be a like-for-like result.
How does the early-withdrawal comparison work?
It grows the current balance at the existing APY and the after-penalty balance at the new APY for the same remaining number of months, then shows the dollar difference and break-even new APY.
Does this include taxes or my bank's exact penalty rules?
No. Enter the exact dollar penalty supplied by your institution. The result does not include taxes, fees, or institution-specific daily accrual and is not financial advice.