Free tool
CD calculator
Updated November 7, 2026. Runs entirely in your browser; nothing you type is sent anywhere.
Enter a deposit, the certificate of deposit's APY and its term in months to estimate the balance and interest at maturity, plus an optional early withdrawal penalty. This is arithmetic only, not financial advice.
How to use the number
- Compare against a flexible savings account with the free APY calculator.
- Saving toward a date? Try the savings goal calculator.
- Keep a cushion you can reach without penalties; see the emergency fund calculator.
Ask your bank for a better rate
Banks often match a competitor's rate or waive a fee if you ask, but most people never make the call. The Bills Kit ($19) gives word-for-word lines for asking providers for a better deal, plus Call Mode. One-time purchase, 14-day refund.
How is CD interest calculated?
Ending balance = deposit × (1 + APY)^(months ÷ 12), assuming the APY is fixed for the term and you hold the CD to maturity. Most banks quote CD rates as APY, which already includes compounding.
What happens if I withdraw early?
Most CDs charge an early withdrawal penalty, often a set number of months of interest. The optional penalty field estimates what you would keep if you cashed out at maturity minus that penalty; check your bank's actual terms.
CD or high-yield savings?
A CD locks in a rate for a fixed term; a savings account rate can change anytime but you can withdraw freely. Compare the CD's total interest here with a savings estimate from the APY calculator.
Is this financial advice?
No. It is simple arithmetic on the numbers you enter. Interest is usually taxable; check your bank's disclosures.
Guidance only, not legal, financial, or tax advice. The calculator does simple arithmetic on the numbers you enter.