Reference Lines and Trendlines in Looker Studio

Available for the following charts:

• Line/Time Series

• Bar/Column Chart

• Combo Chart

• Area Chart

• Scatter Chart

• Bubble Chart

Reference Line Type:

• Metrics: Calculation includes Average, Median, Percentile, Min, Max, and Total.

• Constant value: A custom number that is to be displayed on the Left or Right Y-Axis

• Parameter: If you have set a Parameter in your report. You can select it here.

Editing Charts with Reference Lines

• Changing the chart type will delete any reference lines not supported by the new chart type—for example, Line Chart to Scorecard.

• If you remove a metric from the chart, it will delete any reference lines associated with that metric.

Reference Lines Limitation

• Reference lines are only available for numeric axes. Reference lines on date axes aren't supported.

• Metric-based reference lines calculate based on only the values displayed in the chart. So, for example, if you add a reference line to a bar chart with 10 bars, data from additional bars is not included in the calculation.

• It is not possible to use reference lines in 100% stacked charts.

• Only constant values and parameters reference lines are supported in Stacked columns, stacked bars, and stacked area charts.

Trendlines in Looker Studio (Formerly known as Data Studio)

Trend lines reveal the general tendency of the data on a chart. Trend lines allow you to spot patterns and make predictions from otherwise random data. You can add trend lines to time series and scatter charts.

Trendline Types

1. Linear: Linear trend lines are straight lines that approximate the data on the chart as closely as possible.

2. Exponential: You can use an exponential trendline when an exponential of the form eax+b best represents your data.

3. Polynomial: A polynomial trendline displays data directionality as a curved line. It can help analyze large, highly variable data series.