Use these options to make formatting changes to the trendline that is displayed in your chart.

Trend/Regression Type

Exponential Applies a curved line to display data values that rise or fall at increasingly higher rates. For an exponential trendline, your data should not contain zero or negative values.

This type of trendline uses the following equation to calculate the least squares fit through points:

equation

where c and b are constants, and e is the base of the natural logarithm.

Linear Applies a best-fit straight line to display simple linear data sets that contain data values that increase or decrease at a steady rate.

This type of trendline uses the following linear equation to calculate the least squares fit for a line:

equation

where m is the slope and b is the intercept.

Logarithmic Applies a best-fit curved line to display data values that increase or decrease quickly before leveling out. For a logarithmic trendline, your data can contain negative and positive values.

This type of trendline uses the following equation to calculate the least squares fit through points:

equation

where c and b are constants, and ln is the natural logarithm function.

Polynomial Applies a curved line to display fluctuating data values. Click this option, and then enter a whole number from 2 to 6 in the Order box to determine how many bends (hills and valleys) appear in the curved line. For example, if the value of Order is set to 2, the chart typically displays only one hill or valley, a value of 3 displays one or two, and a value of 4 may display up to three hills or valleys.

This type of trendline uses the following equation to calculate the least squares fit through points:

equation

where b and variable are constants.

Power Applies a curved line to display data values that compare measurements that increase at a specific rate. For a power trendline, your data should not contain zero or negative values.

This type of trendline uses the following equation to calculate the least squares fit through points:

equation

where c and b are constants.

Moving Average Applies a curved trendline to display data values while smoothing out fluctuations in data to show a pattern or trend more clearly. Click this option, and then enter a number, between 2 and the number of data points in the series minus 1, in the Period box to determine the data point averages that are used as the points in the trendline. For example, if Period is set to 2, the average of the first two data points is used as the first point in the moving average trendline, the average of the second and third data points is used as the second point in the trendline, and so on.

This type of trendline uses the following equation:

equation

Trendline Name

Automatic Uses the default trendline name for the trendline/regression type that you select.

Custom Allows you to specify your own trendline name for the trendline/regression type that you select. Click this option, and then type the name that you want in the Custom box.

Forecast

Forward To forecast ahead to show a trend, type the number of future periods that you want in the Forward box.

Backward To include periods in the past to show a trend, type the number of past periods that you want in the Backward box.

Set Intercept Specifies where the trendline crosses the vertical (value) axis. Select this check box, and then type the number that you want to use as the cross point on the vertical axis.

Display equation on chart Displays or hides the equations that were used for calculating the trendline.

Display R-squared value on chart Displays or hides the R-squared value that Microsoft Office Excel automatically calculates to determine the reliability of the trend and accuracy of the forecast.