Average Return Definition

The average return is the simple mathematical average of a series of returns generated over a period of time. An average return is calculated the same way a simple average is calculated for any set of numbers. The numbers are added together into a single sum, and then the sum is divided by the count of the numbers in the set.

There are several return measures and ways to calculate them, but for the arithmetic average return, one takes the sum of the returns and divides it by the number of return figures.

The average return tells an investor or analyst what the returns for a stock or security have been in the past or what the returns of a portfolio of companies are. This is not the same as an annualized return. The average return ignores compounding.

One example of average return is the simple arithmetic mean. For example, suppose an investment returns the following annually over a period of five full years: 10%, 15%, 10%, 0%, and 5%. To calculate the average return for the investment over this five-year period, the five annual returns are added together and then divided by 5. This produces an annual average return of 8%.

Or consider Wal-Mart (NYSE: WMT). Shares of Wal-Mart returned 9.1% in 2014, lost 28.6% in 2015, gained 12.8% in 2016, gained 42.9% in 2017 and lost 5.7% in 2018. The average return of Wal-Mart over those five years is 6.1%, or 30.5% divided by 5 years.

The simple growth rate is a function of the beginning and ending values or balances. It is calculated by subtracting the ending value from the beginning value and then dividing by the beginning value. The formula is as follows:

• (Beginning value - ending value) / beginning value

For example, if you invest $10,000 in a company and the stock price increases from $50 to $100, the return can be calculated by taking the difference between $100 and $50 and then dividing by $50. The answer is 100 percent, which means you now have $20,000.

When looking at the average historical returns, the geometric average is a more precise calculation. The geometric mean is always lower than the average return. One benefit of using the geometric mean is that the actual amounts invested do not need to be known. the calculation focuses entirely on the return figures themselves and presents an "apples to apples" comparison when looking at two or more investments' performance over more various time periods.

The geometric average return is sometimes called the time-weighted rate of return (TWRR) because it eliminates the distorting effects on growth rates created by various inflows and outflows of money into an account over time.

Alternatively, the money-weighted rate of return (MWRR) incorporates the size and timing of cash flows, so it is an effective measure for returns on a portfolio that has received deposits, dividend reinvestments, interest payments, or has had withdrawals. The money-weighted return is equivalent to the internal rate of return where the net present value equals zero.

The simple average of returns is an easy calculation, but it is not very accurate. For more accurate returns calculations, analysts and investors also frequently use the geometric mean or money-weighted return.

For related insight, read more about how to calculate investment returns.