How To Use Logarithmic Scaling In Excel

In this tutorial we are going to look at the Logarithmic Scale option for formatting charts. This option allows you to more easily see the variances between significantly different sets of data, without using a secondary axis.

Here is a table with four sets of data that are significantly different:

If we create a cluster column chart from this data, we’ll get something like this:

It’s easy to visualize Cleveland’s and Pittsburgh’s data, but the others are too low on the scale to detect the variances.

Here’s where the logarithmic scale comes in very handy. Right click on the left axis and choose Format Axis. From there, click on Logarithmic Scale, and select the base you want to use (I left it at base 10):

Choosing this option changes the scaling of the axis from linear to logarithmic. Now each mark on the scale increases exponentially by one (10^1, 10^2, 10^3, etc.). As noted, you can set the base number as you wish from 2 to 1,000:

In this case you might also want to adjust the minimum value on the scaling to 100 to make the chart less dramatic:

And adding a data table while removing the legend makes it even easier for the user to understand the value variances:

Play with the different options here and see what styles and options make your chart look best!

What can you do next?