Free Practice WorkbookWhen you have a large numerical range of data and you want to plot a graph, you will most probably end up with a skewed looking chart like the one below. You want to create an Excel Chart Logarithmic Scale! You can use the logarithmic scale Excel (Excel log scale) in the Format Axis dialogue box to scale your chart by a base of 10.
What this does is it multiplies the vertical axis units by 10, so it starts at 1, 10, 100, 1000, 10000, 100000, 1000000 etc. This scales the chart to show a more even spread, like the image below:
Key Takeaways:
- What is a Logarithmic Scale? – A logarithmic scale is used to represent data that spans multiple orders of magnitude, making it easier to visualize exponential growth or large variations in data.
- How to Apply a Logarithmic Scale – You can set a logarithmic scale by right-clicking the axis in a chart, selecting “Format Axis,” and checking the “Logarithmic scale” option.
- Choosing the Base for Logarithmic Scaling – The default base is 10, but you can modify it (e.g., base 2 or base e) to better suit your data visualization needs.
- Best Use Cases for Logarithmic Charts – Useful for financial data, scientific measurements, and cases where small and large values need to be compared on the same axis.
- Limitations of Logarithmic Scales – Log scales do not support zero or negative values, as logarithms are only defined for positive numbers.
Table of Contents
How to use an Excel Chart Logarithmic Scale
*** Watch our video and step by step guide below with a free downloadable Excel workbook to practice ***
Frequently Asked Questions
How do I apply a logarithmic scale to my Excel chart?
Right-click the axis, select “Format Axis,” and check the “Logarithmic scale” option under “Axis Options.”
What base should I use for a logarithmic scale in Excel?
The default base is 10, but you can change it to another value (e.g., 2 or e) depending on your data distribution.
Can I use a logarithmic scale if my data contains zero or negative values?
No, logarithmic scales only work with positive numbers. You may need to adjust your data or use a different visualization approach.
Why would I use a logarithmic scale instead of a linear one?
A logarithmic scale is useful when your data spans a wide range, as it compresses large values and expands small values for better visualization.
Can I apply a logarithmic scale to both axes in an Excel chart?
Yes, you can set both the X-axis and Y-axis to logarithmic by formatting each axis separately in the chart settings.
John Michaloudis is a former accountant and finance analyst at General Electric, a Microsoft MVP since 2020, an Amazon #1 bestselling author of 4 Microsoft Excel books and teacher of Microsoft Excel & Office over at his flagship MyExcelOnline Academy Online Course.
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