# Certificate of Deposit (CD) – Savings Calculator

### What is a Certificate of Deposit (CD)?

A certificate of deposit is very similar to depositing money into a savings account – the biggest difference being that the money in the CD is usually “locked in” for a period of time (and because of that typically is rewarded with a higher interest rate).

### How is the savings from a CD calculated?

Savings from a compound interest CD is calculated using a simple time value of money financial formula.
$Amount Needed to Invest = Savings Goal / (1 + Interest Rate)^Number of Compounding Periods$
It is important to note that the interest rate result is for each compounding period – to find Annual Percentage Rate (APR) it is then adjusted to an annual rate (for example if the CD is compounded monthly, the Interest Rate result would be multiplied by 12 to find the APR)

### Example

A depositor is looking to have a total savings of \$1,020 after 36 months. The bank is currently offering a rate of 0.75% on CDs (compounded Monthly).
$Amount Needed to Invest = 1020 / (1 + 0.000625)^36$
$Amount Needed to Invest = 1020 / (1.000625)^36$
$Amount Needed to Invest = 1020 / 1.02274$
$Amount Needed to Invest = 999.28$
Therefore, to reach this savings goal, the depositor would need to invest \$999.28

### What is the initial deposit?

The initial deposit is the amount initially invested in the CD.

### What are months?

Months are the amount of total time that the investment is held in the CD.
Most CDs are invested in a period of years, however there are some that are invested for shorter terms (or partial years).

### What is the annual interest rate?

This is the interest rate that is earned annually on the deposit.
The annual interest rate is different than the annual percentage yield (APY).

### What is the compounding period?

The compounding period is how frequently the account is updated with each interest deposit.
Shorter compounding periods typically yield more interest over the term than longer compounding periods with the same interest rate.