*55*

AÂ **log-log plotÂ **is a scatterplot that uses logarithmic scales on both the x-axis and the y-axis.

This type of plot is useful for visualizing two variables when the true relationship between them follows a power law. This phenomenon occurs in many fields in real life including astronomy, biology, chemistry, and physics.

This tutorial shows how to create a log-log plot for two variables in Excel.

**Example: Log-Log Plot in Excel**

Suppose we have the following dataset in Excel that shows the values for two variables, x and y:

Use the following steps to create a log-log plot for this dataset:

**Step 1: Create a scatterplot.**

Highlight the data in the range **A2:B11**.Â

Along the top ribbon, click theÂ **Insert **tab. Within theÂ **ChartsÂ **group, click onÂ **Scatter**.

The following scatterplot will automatically appear:

**Step 2: Change the x-axis scale to logarithmic.**

Right click on the values along the x-axis and clickÂ **Format Axis**.

In the new window that pops up, check the box next toÂ **Logarithmic scaleÂ **to change the x-axis scale.

**Step 3: Change the y-axis scale to logarithmic.**

Next, click on the y-axis and repeat the same step to change the y-axis scale to logarithmic. The resulting plot will look like this:

Notice that the x-axis now spans from 1 to 10 while the y-axis spans from 1 to 1,000. Also notice how the relationship between the variables x and y now appears more linear. This is an indication that the two variables do indeed have a power law relationship.

**You can find more Excel tutorials here.**