Effective Interest Rate (EIR)

The Effective Interest Rate (EIR), also known as Effective Annual Interest Rate (EAR), Annual Equivalent Rate (AER), or Simply Effective Rate, is the Actual Return on a Savings Account or other interest paid investment after taking into account the impact of compounding over time. It’s the interest rate an investor will receive (or pay) in a year after taking compounding into consideration. EIR is employed to check the interest rates between loans with different compounding periods, like weekly, monthly, half-yearly, or yearly. Compare it to the Annual Percentage Rate (APR) which is predicated on interest.

The effective interest rate now and then contrasts in one significant regard from the annual percentage rate (APR): the APR strategy changes over this week by week or month to month financing cost into what might be considered a yearly rate that (in certain pieces of the world) doesn’t consider the impact of aggravating. It likewise uncovers the genuine rate owed in enthusiasm on an advance, a MasterCard, or some other obligation. EIR is additionally called the powerful loan fee, the compelling rate, or the yearly proportional rate.

The EIR or EAR formula is given below:

EIR = (1+i/n)n – 1


i = Stated annual interest rate

n = Number of compounding periods

In comparison, the periodic output using compounding is annualized in the EIR. It is the European Union (EU) standard and several other countries around the world. EIR is an important method for determining the true return on an investment or the actual interest rate on a loan. It is the real return paid on savings or the real cost of a loan because it takes into consideration the results of compounding and any fees charged. The term nominal EIR or nominal APR can (subject to legislation) be accustomed to seek advice from an annualized rate that doesn’t take under consideration front-fees and other costs is included.

Because of compounding, the reported annual interest rate and the effective interest rate may vary considerably. The effective interest rate is critical to identify the best loan or to decide which investment provides the highest return rate. For example, a nominal charge per unit of 6% compounded monthly is such as an efficient rate of interest of 6.17%. 6% compounded monthly is credited as 6%/12 = 0.005 monthly. After one year, the initial capital is increased by the factor (1 + 0.005)12 ≈ 1.0617.

A bank certificate of deposit, an investment account, or an advance offer might be promoted with its ostensible loan cost just as its successful yearly loan cost. The ostensible loan cost doesn’t take mirror the impacts of intensifying interest or even the charges that accompany these monetary items. The viable yearly loan fee is a genuine return. On account of aggravating, the EAR is consistently higher than the expressed yearly loan cost.

When banks pay interest on your savings account, it is advertised that the EIR or EAR would look more appealing than the interest rate implied. In accountancy, the term effective interest rate is used to describe the rate used by the effective interest method to measure interest expenditure or revenue. For example, for a deposit at a stated rate of 10% compounded monthly, the effective annual rate would be 10.47%. Banks will advertise the effective annual rate of interest of 10.47% instead of the stated charge per unit of 10%. Essentially, they show whichever rate appears more favorable.


Information Sources:

  1. corporatefinanceinstitute.com
  2. investopedia.com
  3. wikipedia