# Effective interest method

Effective interest method is an accounting method used to record interest income and interest expense for a given period of time. It requires that the interest rate used to calculate the interest amount should equal the rate used to amortize the principal. This method amortizes the difference between the principal amount and the original issue price for fixed-income investments and loans, resulting in a more accurate recording of interest income and interest expense. Under this method, the interest amount is calculated using the effective interest rate, which is the rate earned over the life of the investment or loan.

## Example of effective interest method

• An example of the effective interest method is when a company takes out a loan for \$1 million with an interest rate of 7%. The effective interest rate is calculated by taking the interest rate and multiplying it by the remaining principal balance at the beginning of each period. The company would then pay \$70,000 in interest each year, and the remaining principal balance would be reduced by \$930,000, leaving a remaining balance of \$70,000.
• Another example of the effective interest method is when a company invests in a bond with a face value of \$1 million and an interest rate of 5%. The effective interest rate is calculated by taking the interest rate and multiplying it by the remaining principal balance at the beginning of each period. The company would then receive \$50,000 in interest each year, and the remaining principal balance would be reduced by \$950,000, leaving a remaining balance of \$50,000.

## Formula of effective interest method

The formula to calculate the effective interest rate is as follows:

Effective Interest Rate = ((Future Value/Principal) - 1)/Time Period

Where:

Future Value = The amount to be received or paid at the end of the loan or investment period

Principal = The amount borrowed or invested initially

Time Period = The number of periods for which the loan or investment is held

The effective interest rate is the rate of interest that is earned over the life of the loan or investment. It takes into account the total return on the investment or loan, including both the interest earned and the principal paid or received. The effective interest rate is a more accurate way to measure the return on an investment or loan compared to the annual interest rate. It also allows for more accurate comparison between different types of investments or loans.

The formula to calculate the interest amount using the effective interest rate is as follows:

Interest Amount = Principal x Effective Interest Rate x Time Period

Where:

Principal = The amount borrowed or invested initially

Effective Interest Rate = The rate of interest earned over the life of the loan or investment

Time Period = The number of periods for which the loan or investment is held

The interest amount is the amount of interest that is earned or paid over the life of the loan or investment. It is calculated by multiplying the principal amount by the effective interest rate and then by the time period. This formula allows for more accurate calculation of the interest amount compared to the annual interest rate, as it takes into account the total return on the investment or loan including both the interest earned and the principal paid or received.

## When to use effective interest method

The effective interest method is used in a variety of financial transactions, including:

• Recording interest income and expenses for a period of time;
• Amortizing the difference between the principal amount and the original issue price for fixed-income investments and loans;
• Calculating the interest amount using the effective interest rate, which is the rate earned over the life of the investment or loan;
• Calculating the present value of future cash flows;
• Estimating the fair value of investments;
• Calculating the value of an annuity;
• Assessing the value of a bond;
• Determining the yield of an investment; and
• Analyzing the cost of capital for a business.

## Types of effective interest method

The effective interest method is an accounting method used to record interest income and interest expense for a given period of time. There are several types of effective interest method, including:

• Straight-Line Method: This is the simplest form of the effective interest method and involves amortizing the difference between the principal amount and the original issue price over the term of the loan or investment.
• Modified Effective Interest Method: This method allows for a more accurate recording of interest income and interest expense by factoring in the expected life of the investment or loan.
• Capitalized Interest Method: This method is used when the principal amount is greater than the original issue price. In this case, the interest is capitalized, or added to the principal amount, until it is equal to the original issue price.
• Declining Balance Method: This method amortizes the difference between the principal amount and the original issue price over the life of the loan or investment, with the interest amount decreasing each period.
• Constant Yield Method: This method is based on the assumption that the amount of interest income and expense earned over the life of the investment or loan will remain constant.

## Advantages of effective interest method

The effective interest method has several advantages. These include:

• Improved accuracy in the recording of interest income and expense - As the effective interest rate is used to calculate the interest amount, the interest amount is more likely to match the actual rate earned on the investment or loan. This reduces the risk of errors in recording the correct interest amount.
• Increased transparency - The effective interest method provides more information about the interest rate used to calculate the interest amount, making it easier for investors and lenders to understand the true cost of their investments or loans.
• Improved cash flow management - As the interest amount is calculated based on the effective interest rate, it can help businesses better manage their cash flow, as they know the exact amount of interest they will be paying or receiving.

## Limitations of effective interest method

The effective interest method has several limitations. These include:

• The method relies on the accuracy of the effective interest rate calculation. If the rate is incorrect, the interest income or expense recorded will be inaccurate.
• The effective interest method requires upfront calculation and preparation of the amortization schedule, which can be time consuming.
• The method does not account for credit risk, so if the borrower defaults, the interest income may not be properly recorded.
• The method does not take into account the effect of compounding, so it may understate the interest income or expense for longer-term investments.
• The method does not reflect changes in market rates, so it may not accurately reflect the interest income or expense.

 Effective interest method — recommended articles Real rate of return — Net present value (NPV) — Effective annual interest rate — Economic value of equity — Future value — Annualized rate — Annual depreciation — Modified internal rate of return — Straight line amortization