How to Calculate Average Accounting Return

Average accounting return is a key financial metric used to evaluate the performance of an investment portfolio. It represents the average annual return generated by an investment over a specific period, adjusted for compounding effects. This guide explains how to calculate it, when it's useful, and how to interpret the results.

What is Average Accounting Return?

Average accounting return is a measure of the average annual return on an investment, calculated by dividing the total return by the total number of years the investment was held. Unlike simple arithmetic mean, it accounts for compounding effects over time.

This metric is commonly used in finance to compare the performance of different investments or investment strategies over the same period. It's particularly useful for evaluating the performance of mutual funds, pension funds, and other long-term investments.

How to Calculate Average Accounting Return

To calculate average accounting return, you'll need:

The initial investment amount (principal)
The final value of the investment after the holding period
The number of years the investment was held

The calculation process involves these steps:

Determine the total return of the investment
Divide the total return by the number of years
Express the result as a percentage

Note: Average accounting return is different from the geometric mean return, which accounts for compounding effects more accurately. For most financial reporting purposes, average accounting return is preferred.

The Formula

Average Accounting Return = [(Final Value / Initial Investment) - 1] / Number of Years

Where:

Final Value = The value of the investment at the end of the period
Initial Investment = The amount invested at the beginning
Number of Years = The total holding period in years

The result is typically expressed as an annualized percentage. For example, if the calculation yields 0.08, this represents an 8% average annual return.

Worked Example

Let's calculate the average accounting return for an investment that grew from $10,000 to $15,000 over 5 years.

Calculate the total return: $15,000 - $10,000 = $5,000
Divide by the initial investment: $5,000 / $10,000 = 0.5 or 50%
Divide by the number of years: 50% / 5 = 10% per year

Therefore, the average accounting return for this investment is 10% per year.

Interpreting the Result

A positive average accounting return indicates that the investment grew over time, while a negative value suggests a loss. The result should be compared to relevant benchmarks or the investor's expectations.

Key considerations when interpreting the result:

Risk-adjusted returns: Compare the return to the level of risk taken
Time horizon: Consider whether the return is sustainable over the long term
Inflation: Adjust for inflation if comparing across different periods
Tax implications: Account for any tax effects on the investment

Remember that past performance is not indicative of future results. Always consider the investment's risk profile and consult with a financial advisor before making investment decisions.

FAQ

What's the difference between average accounting return and simple arithmetic mean?

Average accounting return accounts for compounding effects by dividing the total return by the number of years, while simple arithmetic mean calculates the average of individual annual returns without considering compounding.

When should I use average accounting return instead of geometric mean return?

Average accounting return is preferred for financial reporting and investor communications, while geometric mean return is more accurate for comparing investment performance over time.

How does inflation affect average accounting return calculations?

Inflation can be accounted for by adjusting the final value of the investment for inflation before performing the calculation.

Can average accounting return be negative?

Yes, if the investment's final value is less than its initial investment, the average accounting return will be negative.

What's the difference between average accounting return and annualized return?

Average accounting return is calculated by dividing the total return by the number of years, while annualized return accounts for compounding effects by using the formula: (1 + total return)^(1/n) - 1.