How this calculator works
The calculator treats the entered rate as APY, which already reflects a year of compounding. It applies that effective yield for the fraction of a year represented by the CD term. The penalty scenario estimates a specified number of months of simple interest.
What affects a CD return
Deposit, APY, term, compounding convention, and withdrawal timing affect the result. Banks may calculate interest daily, credit it on a schedule, impose minimum deposits, or offer promotional and callable products with additional rules.
Real-world example
A $10,000, 12-month CD at 5% APY reaches approximately $10,500 at maturity. A three-month-interest penalty is roughly $125 under this simplified estimate, although an actual institution may calculate the penalty differently.
Common mistakes
- Confusing APR with APY.
- Comparing CDs with different terms without considering reinvestment risk.
- Assuming every early-withdrawal penalty is limited to earned interest.
- Ignoring deposit-insurance limits and ownership categories.
When to use this calculator
Use it to compare maturity values and understand the cost of potentially breaking a CD. Confirm the institution's disclosure, grace period, renewal rules, and penalty formula before opening an account.
FAQ
Is APY the same as the interest rate?
APY reflects the effect of compounding over one year, while a nominal interest rate may not.
Can a CD lose principal to a penalty?
Some account agreements may allow a penalty to exceed accrued interest. Review the institution's disclosure.
Are CDs insured?
Eligible deposits at insured institutions are generally covered within applicable limits and ownership categories; verify the institution and account.