CD Calculator

How to use this CD calculator

Enter the amount you plan to deposit, the APY your bank or credit union is offering, and the term of the CD in months. The calculator instantly shows your value at maturity, the interest earned over the term, and a clear breakdown of how much of the ending balance is your original deposit versus growth. Adjust the sliders to compare offers — a slightly higher APY or a longer term can make a meaningful difference by the time the CD matures.

How this is calculated

A certificate of deposit locks in a fixed rate for a fixed term. Because banks quote CDs using APY (annual percentage yield), the rate already accounts for compounding within the year, so we don't need to compound it again. We convert the term to years (years = months ÷ 12) and grow the deposit by the effective annual yield: maturity = deposit × (1 + APY) ^ years. The interest earned is simply the maturity value minus your original deposit. This is an educational estimate, not investment advice — see our disclaimer.

A worked example

Suppose you deposit $10,000 into a 12-month CD paying a 4.5% APY. Twelve months is one year, so the math is straightforward: $10,000 × (1 + 0.045) = $10,450 at maturity, which is $450 of interest. Stretch that same deposit and rate to a 24-month term and the balance grows to about $10,920 — roughly $920 in interest — because the second year earns yield on the first year's gains too. The longer the term and the higher the APY, the steeper that growth becomes.

Try CD laddering

Locking all your cash into one long CD means you can't touch it without a penalty, and you miss out if rates rise. A CD ladder solves both problems. Instead of putting $10,000 into a single 5-year CD, you split it into five $2,000 CDs maturing one year apart — 1-year, 2-year, 3-year, 4-year, and 5-year. Each year one CD matures, giving you access to cash; you then reinvest it into a new 5-year CD at whatever rate is available. Over time you hold mostly higher-yielding long-term CDs while still having money come due every year. It's a simple way to balance liquidity against the better rates that longer terms usually pay.

CD or high-yield savings?

CDs reward you for committing your money for a set period, often with a slightly higher rate and the certainty of a locked-in yield. The trade-off is access: pulling money out early usually triggers a penalty. A high-yield savings account pays a competitive rate too, but the rate can change at any time and you can withdraw whenever you like. If you may need the cash soon, flexibility wins; if you can leave it untouched, a CD's fixed rate can be worth it. Compare the two side by side with our high-yield savings calculator.