In business, measuring sales trends is an important part of planning for the future. For each product, you need to estimate the future demand for the product, whether that demand will increase or decrease, and by how much. Knowing the sales trend percentages helps you make these predictions. To find the sales trend percent, you need to know the sales amounts for the base year and the year for which you want to calculate the percent. Sales trend percents are measured in relation to the base year.

Identify the base year that you will use for your calculations and the sales for that year. For example, you might want to use 2010 as the base year.

Divide the current year's sales by the base year's sales. For example, if in 2010 you did $100,000 of sales, and in 2014, you did $105,400, divide $105,400 by $100,000 to get 1.054.

Multiply the previous result by 100 to convert from a decimal to a percent to find the sales trend percent. In this example, multiply 1.054 by 100 to find the sales trend percent equals 105.4 percent of the base year's sales.