Specify a Logarithmic Scale (Report Builder and SSRS)
If you have data that is logarithmically proportional, you may want to consider using a logarithmic scale on the chart. This helps improve the appearance of the chart by making your data more manageable. Most logarithmic scales use a base of 10.
This feature is only available on the value axis. The value axis is usually the vertical, or y-axis. On bar charts, however, it is the horizontal, or x-axis.
If your axis is logarithmic, all other properties relating to the axis will be scaled logarithmically. For example, if you specify a base-10 logarithmic scale on your axis, setting an axis interval of 2 will generate intervals in magnitudes of 10 to the power of 2, or 100. This means your axis values will read 1, 100, 10000, instead of the default result of 1, 10, 100, 1000, 10000.
You can create and modify report definitions (.rdl) in Report Builder and in Report Designer in SQL Server Data Tools. Each authoring environment provides different ways to create, open, and save reports and related items. For more information, see Designing Reports in Report Designer and Report Builder (SSRS) on the Web at microsoft.com.
To specify a logarithmic scale
Right-click the y-axis of your chart, and click Vertical Axis Properties. The Vertical Axis Properties dialog box appears.
In Axis Options, select Use logarithmic scale.
In the Log base text box, type a positive value for the logarithmic base. If no value is specified, the logarithmic base defaults to 10.