# Trend lines A trend line is a visual representation of the direction of values over a period of time. Trend lines show trends over time, by visualizing the direction of values and how fast the values change. For information about how to create trend lines, see [Adding trend lines to visualizations](https://help.qlik.com/en-US/sense/May2026/Subsystems/Hub/Content/Sense_Hub/Visualizations/add-trend-and-reference-lines.htm#AddTrendLine). [Adding trendlines to line and bar charts](https://play.vidyard.com/fwWiMDpwQe8JAEj5sti18w) ## Which visualizations have trend lines | Visualization | Trend lines | | --- | --- | | Bar chart | Yes | | Line chart | Yes | ## When to use trend lines A single trend line can be added to a chart to smooth out fluctuations in data, and to show any trends more clearly. More than one trend line can be added to a chart, showing different types of trends or different values. ## Types of trend lines ### Average An average trend line shows the average value of the data, for the time period being analyzed. A bar chart showing sales per month. An average trend line is shown with a dashed red line. A bar chart showing sales per month. An average trend line is shown with a dashed red line. A bar chart showing sales per month. An average trend line is shown with a dashed red line. ![A bar chart showing sales per month. An average trend line is shown with a dashed red line.](https://help.qlik.com/en-US/sense/May2026/Subsystems/Hub/Content/Resources/Images/ui_gen_TrendLinesAverage_922x603.png) ### Linear A linear trend line shows increase or decrease of values at a steady rate. Linear trend lines are usually used with simple linear data sets. A bar chart showing sales per month. An linear trend line is shown with a dashed red line. A bar chart showing sales per month. An linear trend line is shown with a dashed red line. A bar chart showing sales per month. An linear trend line is shown with a dashed red line. ![A bar chart showing sales per month. An linear trend line is shown with a dashed red line.](https://help.qlik.com/en-US/sense/May2026/Subsystems/Hub/Content/Resources/Images/ui_gen_TrendLinesLinear_929x602.png) ### Polynomial (second, third, fourth degree) A polynomial trend line is a curved line used on fluctuating data. The number of data fluctuations can determine the order of the polynomial. A second degree polynomial trend line has one hill or valley, a third degree polynomial trend line has up to two hills or valleys, and a fourth degree polynomial has up to three hills or valleys. A bar chart showing sales per month. Polynomial trend lines of second, third, and fourth degree are shown with dashed red, yellow, and green lines respectively. A bar chart showing sales per month. Polynomial trend lines of second, third, and fourth degree are shown with dashed red, yellow, and green lines respectively. A bar chart showing sales per month. Polynomial trend lines of second, third, and fourth degree are shown with dashed red, yellow, and green lines respectively. ![A bar chart showing sales per month. Polynomial trend lines of second, third, and fourth degree are shown with dashed red, yellow, and green lines respectively.](https://help.qlik.com/en-US/sense/May2026/Subsystems/Hub/Content/Resources/Images/ui_gen_TrendLinesPolynomialsAll_932x606.png) ### Exponential An exponential trend line is a curved line used when data values rise or fall at increasingly higher rates. A bar chart showing sales per month. An exponential trend line is shown with a dashed red line. A bar chart showing sales per month. An exponential trend line is shown with a dashed red line. A bar chart showing sales per month. An exponential trend line is shown with a dashed red line. ![A bar chart showing sales per month. An exponential trend line is shown with a dashed red line.](https://help.qlik.com/en-US/sense/May2026/Subsystems/Hub/Content/Resources/Images/ui_gen_TrendLinesExponential_931x604.png) ### Logarithmic A logarithmic trend line is a curved line used when the rate of change in data increases or decreases quickly, before leveling out. A bar chart showing sales per month. A logarithmic trend line is shown with a dashed red line. A bar chart showing sales per month. A logarithmic trend line is shown with a dashed red line. A bar chart showing sales per month. A logarithmic trend line is shown with a dashed red line. ![A bar chart showing sales per month. A logarithmic trend line is shown with a dashed red line.](https://help.qlik.com/en-US/sense/May2026/Subsystems/Hub/Content/Resources/Images/ui_gen_TrendLinesLogarithmic_929x604.png) ### Power A power trend line is a curved line used with data sets that compare measurements that increase at specific rates. A bar chart showing sales per month. A power trend line is shown with a dotted red line. A bar chart showing sales per month. A power trend line is shown with a dotted red line. A bar chart showing sales per month. A power trend line is shown with a dotted red line. ![A bar chart showing sales per month. A power trend line is shown with a dotted red line.](https://help.qlik.com/en-US/sense/May2026/Subsystems/Hub/Content/Resources/Images/ui_gen_TrendLinesPower_935x608.png) ## Learn more * [Adding trend and reference lines to visualizations](https://help.qlik.com/en-US/sense/May2026/Subsystems/Hub/Content/Sense_Hub/Visualizations/add-trend-and-reference-lines.htm) * [Creating a drill-down dimension](https://help.qlik.com/en-US/sense/May2026/Subsystems/Hub/Content/Sense_Hub/Dimensions/create-drill-down-dimension.htm)