Size and color details can be formatted in the marks card in Tableau. Learning how to format sizes in the marks card in Tableau is one of the basic skills you must learn. The Tableau’s Size property allows you to encode data by assigning different sizes to the marks in a data view.

Depending on whether you use a discrete or continuous field, you will add either categorical or quantitative size encodings. 

When can you use the Tableau Size shelf

While you can drop a discrete dimension on the size shelf, this rarely, if ever, makes sense, so we will focus on how continuous measures work. 

When you place a continuous field on  Size on the Marks card, Tableau draws each mark with a different size using a continuous range. The smallest value is assigned the smallest sized mark and the largest value is represented by the largest mark. 

How to use Tableau Size Property

  1. Let’s return to the chart that we started on the hierarchies and sorting and then continue with color. Currently, the chart has a series of bars depicting sales broken out by department and category.  It is color encoded by profit.  Let’s see what insight might pop out by using the size shelf. 
  1. Drag Product Base Margin to the Size shelf.   
  1. Notice the following: 
  • The Marks card now shows SUM(Profit) on the Colors Shelf with the colored dots next to it.  It also shows SUM(Product Base Margin) on the size shelf with the smaller/larger circle icon. This helps you quickly see which variables you have where.  
Tableau Size
  • We also have two legends on the right-hand side of the screen – one for color and one for size.  This helps you and your users interpret what they are seeing and the meaning of the chart.  These are essential!   
  1. A Tableau chart can encode a lot of information at once – more than most people are typically used to.  It’s your job to provide maximum insight with as much simplicity and ease of use as possible.  Giving your users cues about where to look and how to interpret these charts is a must to having your insights adopted and acted upon. 
  1. Let’s say you wanted to see how your chart might look if we were to move the measures around.  A fast way to do this is to use the “Cycle Fields” function. 
  1. Go to the Analysis menu and at the bottom choose Cycle Fields.  Notice how your viz changes.  Click it again, then again, noticing the changes each time.  Decide what you think best provides insight and keep that. 
Tableau Sizing
  1. Also, you can change the sizing of the marks.  Perhaps, everything is too big or too small for your liking.  Click on the Size button and move the slider up or down to change the size. 

The Marks card not only allows size modifications, but also features more formatting features like labels, level of detail, and tooltip. Watch out for our upcoming blogs about those. Or maybe consider getting our individual or corporate training for enhanced proficiency in Tableau.