CD Calculator (Certificate of Deposit)

A CD is a time-deposit account at a bank or credit union. You agree to leave a fixed amount of money on deposit for a fixed term (usually 3 months to 5 years) in exchange for a guaranteed interest rate that is typically higher than a regular savings account. Your funds are locked until the maturity date; pulling money out early triggers an early-withdrawal penalty. CDs at US banks are insured by the FDIC and at credit unions by the NCUA, so the principal is safe as long as you stay under the coverage limit.

APR (Annual Percentage Rate) is the nominal annual interest rate before compounding. APY (Annual Percentage Yield) is the effective annual return after compounding. APY is equal to or higher than APR for nonnegative rates because reinvested interest earns more interest. US banks are required by Regulation DD to advertise CDs in APY, which is the number you should compare across offers. This calculator treats the input as the advertised effective APY and back-solves the periodic rate from it.

A CD ladder splits one large deposit across multiple CDs with staggered maturity dates. A common 5-year ladder puts equal amounts into a 1-year, 2-year, 3-year, 4-year, and 5-year CD. Each year one CD matures and you roll it into a new 5-year CD at whatever the current rate is. The ladder keeps a portion of your money available every 12 months without paying penalties, while still earning the higher rates that longer-term CDs offer. It also smooths out interest-rate risk: you are not locked in at a single rate at a single point in time.

Yes. CDs at FDIC-insured US banks are protected up to $250,000 per depositor, per insured bank, per ownership category. The same coverage applies at NCUA-insured credit unions. If you have more than $250,000 to deposit, split it across separate banks or different ownership categories (individual, joint, trust) to stay fully insured. Brokered CDs are also covered, but only by the underlying issuing bank, so always verify the bank behind a brokered offering before stacking deposits.

The penalty depends on the institution and account agreement. Banks may state it as a number of days or months of interest, a fixed dollar amount, or another disclosed method. If you withdraw before enough interest has accrued, some institutions can deduct the remainder from principal. This calculator reconstructs the nominal interest rate implied by your APY and compounding frequency, then estimates the entered months of interest in equal monthly slices. Check the CD disclosure for the actual rate basis, day-count method, and penalty.