How to Find Y-Intercept of a Graph in Excel

The y-intercept of a graph represents the point where a line crosses the y-axis when x is equal to zero.

To find the y-intercept of a line in Excel, we can use the INTERCEPT function.

This functions uses the following syntax:

INTERCEPT(known_y’s, known_x’s)

where:

known_y’s: The range of y-values
known_x’s: The range of x-values

The following example shows how to use this function in practice to calculate the y-intercept of a graph in Excel.

Step 1: Create the Data

First, let’s create a dataset with two variables in Excel:

Step 2: Calculate Y-Intercept Value

Next, let’s type the following formula into cell E1 to calculate the y-intercept for this dataset:

=INTERCEPT(B2:B21, A2:A21)

The following screenshot shows how to use this formula in practice:

From the output we can see that the y-intercept is 12.46176.

Step 3: Visualize the Y-Intercept Value

To visualize the y-intercept value, we can create a scatterplot and add a trendline.

To do so, highlight the values in the range A2:B21, then click the Insert tab, then click Insert Scatter (X, Y) in the Charts group and click the first option to create a scatterplot:

The following scatterplot will appear:

Next, click the green plus sign in the top right corner of the plot, then click the arrow next to Trendline and click More Options:

In the Format Trendline panel that appears on the right side of the screen, click the Linear trendline option, then check the box next to Display Equation on chart:

The linear trendline and the equation for the linear trendline will be displayed on the chart:

From the output we can see the formula for the linear trendline:

y = 0.917x + 12.462

This means that when x is equal to zero, the estimated value of y (i.e. the y-intercept) is 12.462.

If we imagine that the linear trendline extends all the way to the left until it reaches the y-axis, it does indeed look like the line would cross the y-axis at a value of y = 12.462.