What is the Sales Growth Rate? The Sales Growth Rate of a business is the the rate at which it is growing its sales year over year. The Rule #1 Sales Growth Rate calculator helps you determine this rate of growth. Sales Growth Rate is one of the Big 5 Numbers required to determine whether a company may be a Rule #1 'wonderful business'. The average annual growth rate (AAGR) formula is: AAGR = (Growth Rate in Period A + Growth Rate in Period B + Growth Rate in Period C + [Other Periods]) / Number of Periods. Let's look at an example. Assume that Company XYZ records revenues for the following years: Year Revenue 2016 $1,000,000 2017 $1,200,000 2018 $1,300,000 2019 $1,400,000 Next, divide that number by the past period's revenue. Multiply that result by 100 to give you the percentage of sales growth between the two periods. For example, if your business had sales of $2,500 this month, and sales of $2,000 in the same month last year, the difference is a $500 increase in sales.