Display Trendlines in Current Default Charts

Trendlines, also known as lines of best fit or regression lines, graphically illustrate trends in data series and are commonly used when charting predictions. A trendline is typically a line or curve that connects or passes through two or more points in the series, displaying a trend.

You can display trendlines in the current default bar, line, area, bubble, and scatter charts.

You can specify the following types of trendlines:

Linear
Use a linear trendline when your data values increase or decrease along a straight line at a constant rate. For example, if your chart displays a steady increase in revenue by product line over time, a linear trendline might be appropriate.
Polynomial
Use a polynomial trendline when your data values both increase and decrease. For example, if your chart displays both increases and decreases in revenue by product line over time, a polynomial fit trendline might be appropriate.
Logarithm
Use a logarithmic trendline when your data values increase or decrease rapidly and then levels out. For example, if your chart displays a rapid decrease in revenue by product line over time and then a plateau, a logarithmic trendline might be appropriate.
Moving Average
Use a moving average trendline when your data values fluctuate and you want to smooth out the exceptions to see trends. For example, if your chart displays large fluctuations in revenue by product line over time, but you know that some data points are exceptions, a moving average trendline might be appropriate.

If you are not sure which trendline type to use, try each type to see which one best fits most of your data points. For example, a linear trendline will not fit most points on a scatter chart with widely spread data points.

Trendlines do not support color transparency.

Procedure

Select the chart object.
In the Properties pane, click Trendlines.
Click the new button and click a trendline type.
Define the trendline by specifying the following options.
The options that are available depend on the type of trendline you chose.
- To set the order, or degree, of a polynomial trendline, in the Order box, type a value between 2 and 6.
- To set the number of prior periods to include when calculating the moving average trendline, type a value in the Periods box.
- If you have more than one series on your chart, in the Based on list, click the data you want to use for the trendline.
- To customize the style of this trendline, click Line Styles and customize the line color, weight, style, and transparency.
- To customize the trendline label in the legend, click Label and choose None, Automatic, or Custom.
- To display the trendline equation, click Show equation.
- To display the R-squared value of the trendline, click Show R-squared value.