# effective interest rate

Also found in: Dictionary, Thesaurus, Legal, Acronyms, Encyclopedia, Wikipedia.

## Effective Interest Rate

The annual rate at which an investment grows in value when interest is credited more often than once a year.

## Effective Interest Rate

The interest rate on a debt or debt security that takes into account the effects of compounding. For example, if one has a fixed-income investment such as certificate of deposit that pays 3% in interest each month, the effective interest rate is more than 3% because compounding the interest results in a (slightly) greater principal each month on which the interest rate is calculated. In this example, the effective interest rate is calculated thus:

Effective interest rate = (1 + .03/12)^12 - 1 = .0304 = 3.04%, where .03 is the simple interest rate and 12 is the number of times in a year interest is compounded. It is also known as the annual effective rate or the annual equivalent rate. See also: Stated annual interest rate, annual percentage yield.

Effective interest rate = (1 + .03/12)^12 - 1 = .0304 = 3.04%, where .03 is the simple interest rate and 12 is the number of times in a year interest is compounded. It is also known as the annual effective rate or the annual equivalent rate. See also: Stated annual interest rate, annual percentage yield.

## effective interest rate

the INTEREST RATE payable on the purchase price of a BOND. For example, a bond with a face value of £100 and a NOMINAL (COUPON) INTEREST RATE of 5% generates a nominal return of £5 per year. If, however, the bond can be purchased for £50 on the open market, then the effective interest rate now rises to 10%, representing a 10% return on the £50 invested. The lower the purchase price of a bond with a given nominal rate of interest, the higher its effective rate of interest will be, and vice-versa. There is thus an inverse relationship between the price paid for a bond and its effective rate of interest (sometimes called the interest YIELD).## effective interest rate

The actual interest rate of a loan,regardless of the face interest rate or the rate quoted.See *annual percentage rate*.