CD Calculator - Maturity Value and Interest (2026)

A certificate of deposit is a time deposit that holds a fixed amount for a stated term in exchange for a fixed APY. Terms commonly range from 3 months to 60 months, and the bank guarantees the APY for the full term even if market rates fall. Unlike savings, withdrawing before maturity triggers a penalty, usually 1 to 6 months of interest.

Maturity value is calculated as Deposit x (1 + APY)^(months/12). For example, $10,000 at 4.50% APY for 12 months becomes $10,000 x 1.045 = $10,450, earning $450. For 24 months the same deposit becomes $10,920, earning $920, because APY already includes compounding and the exponent is years.

A 12-month CD at 4.50% APY slightly beats a 4.25% high-yield savings account by $25 per $10,000 over one year ($10,450 vs $10,425). The CD math wins only when the cash will not be needed, because the savings account rate is variable and stays liquid. Financial planning guidelines suggest using a CD to lock a rate and a HYSA for emergency money.

In July 2026 a good 12-month CD paid 4.00% to 4.40% APY, compared with the FDIC national average of 1.68% for 12-month CDs. Anything above 4.00% was in the top quartile of nationally available offers, while 3.00% to 3.50% was average for competitive online banks. Always compare the APY net of fees.

Penalties are avoided by matching maturity to the date the money is needed and keeping 1 to 3 months of expenses in liquid savings. A CD ladder splits $20,000 across 6, 12, 24 and 36-month CDs so a portion matures every 6 to 12 months. Disclosures typically state the penalty as 90 to 180 days of interest.

On a $10,000 CD for 12 months, a 1 percentage point increase from 3.50% to 4.50% raises maturity from $10,350 to $10,450, adding $100 in interest. For 24 months the same 1-point increase raises maturity from $10,712 to $10,920, adding $208. On $25,000 for 24 months the gain is $520.

This calculator does not include: (1) federal or state income tax on interest, which is generally taxable in the year credited; (2) compounding variations like daily vs monthly crediting that can shift maturity by $2 to $5 per $10,000; or (3) promotional, bump-up or callable features and fees that alter the disclosed APY.

Yes, CDs from FDIC-insured banks are insured up to $250,000 per depositor, per insured bank, per ownership category, and credit union share certificates have parallel NCUA coverage. Coverage applies to principal plus accrued interest within the limit. Amounts above $250,000 at one bank in one category are uninsured.

Retail CD terms typically run 3, 6, 12, 24, 36 and 60 months, with some banks offering 1-month or 84-month options. You may withdraw any day, but withdrawing before the maturity date triggers the early-withdrawal penalty, often 3 months interest for terms under 12 months and 6 months for terms 24 months or longer.

At maturity the bank either transfers the full balance to a linked account, holds it in a settlement account, or automatically renews into a new CD at the then-current APY after a 7 to 10-day grace period. Automatic renewal may set a new APY below the original 4.50%, and a calendar reminder dated 10 days before maturity prevents an unwanted rollover.