CD Calculator

Use the APY and term from the actual CD

Enter the amount deposited at opening, the stated annual percentage yield and the term in months. The calculator converts the term to a fraction of a year and applies the APY as an effective annual yield.

This is a maturity-value projection. It assumes no additional deposits or withdrawals during the term, which matches many traditional CD structures but may not match every bank product.

• Initial deposit
• Advertised APY
• Term in months

How the CD maturity estimate works

Estimated maturity value = deposit × (1 + APY)^(term in years). Interest earned is the maturity value minus the starting deposit. This treats APY as an effective annual yield and therefore does not apply a second compounding frequency on top of it.

A six-month term, for example, uses one-half of a year. Actual banks may credit interest using daily calculations or have specific maturity-date conventions, so small differences can occur.

Worked example: one-year certificate of deposit

With a 10,000 deposit, a 5% APY and a 12-month term, the simplified estimate is 10,500 at maturity and 500 of interest before tax, assuming the stated APY applies for the term.

For a shorter term, do not simply multiply APY by the fraction of a year when precision matters. The calculator uses compound growth over the fraction of the year.

Check the early-withdrawal penalty before locking money away

The FDIC advises consumers comparing CDs to determine whether a CD can be redeemed early and what fee applies. An advertised APY does not tell you the cost of needing the money before maturity.

This calculator does not subtract an early-withdrawal penalty because penalty structures vary by product. If you may need the money, compare the product’s liquidity terms with an accessible savings option rather than comparing APY alone.

Maturity and automatic renewal can change the next step

Some CDs automatically renew when the term ends unless instructions are provided during a grace period. The renewal rate may differ from the original rate. Check the bank’s maturity notice and renewal policy instead of assuming the same APY continues into a new term.

For a CD ladder, calculate each certificate separately because different deposits, maturity dates and APYs should not be blended into one fictitious term.

Common CD comparison mistakes

Do not compare a long-term CD with a liquid savings account on APY alone. Term, early-withdrawal penalties, renewal rules, deposit insurance eligibility and your expected need for cash all matter.

Also avoid entering a nominal annual rate into the APY field unless the product actually quotes that number as APY. Use the APY Calculator when you need to convert a nominal rate first.

When a CD ladder changes the calculation

A CD ladder divides money among certificates with different maturity dates instead of placing the full balance into one term. Each certificate can have its own APY, so a single blended CD calculation can hide when cash becomes available and which rate applies to each portion.

To model a ladder with this calculator, calculate each certificate separately and keep a simple schedule of deposit, maturity date and projected maturity value. The combined total can then be added after each individual estimate is calculated on its own terms.

Use The Result In The Next Calculation

Use the CD result for a fixed-term deposit using the APY you enter. If you are comparing accounts with different compounding conventions but no fixed term, use the APY calculator first.