how do you combine a line chart and an area chart into one in this example I have an area chart by region with a line overlaying on top of it let's add a new sheet and build this in tableau. first we're going to build a line chart using date we'll use month of date if I right click order date drag it to columns I get the choice and I'm going to choose month. I'm going to grab sales and put it on rows that gives me a line chart in order to change this into an area chart I need to grab a dimension like a region and put it on color. also change it to an area chart on the marks card. now I want to Overlay a line on top of this I can hold the control key down and drag sum of sales to the right to create a second axis on the second axis I'm going to change it to a line notice that when I swap between the two axes you're getting two different marked cards and now I can create a dual axis by clicking the drop down on the second sum of sales and selecting dual axis. you'll have to synchronize your access you'll see that this one goes to 140 000 and this one goes to 350 000. let's synchronize them by right-clicking the axis and selecting synchronize if you want the lines to overlay on top here you have to go to analysis stacked marks on and you have a line overlaying your area chart if you want you can also remove region from the line to have one Total Line now I have a gray line on top of my area chart hope this helps.