How to make a Venn diagram
The trick is to fill the diagram from the middle outwards. Pick a set expression below to see exactly which region it means.
Step by step
- List each set and its members. Example: English = Ana, Ben, Chen, Dev, Eli; Spanish = Chen, Dev, Gil, Hugo.
- Find the intersection, the members in both: Chen and Dev. Write them in the overlap first.
- Fill the “only” regions with what’s left: Ana, Ben and Eli (English only); Gil and Hugo (Spanish only).
- Place anyone in neither set outside the circles but inside the box.
- Check the counts: each circle’s regions should add up to its set size (English: 3 + 2 = 5).
For three sets, start at the centre (in all three), then the three pairwise overlaps, then the “only” regions. The Venn diagram maker does this sorting automatically when you list the items.
Set notation, lit up
A = speaks English, B = speaks Spanish. Pick an expression to see which region it means.
A ∩ B = { Chen, Dev }
A ∩ B is the intersection — in both A and B. Jo speaks neither, so Jo sits outside both circles.
Questions
Where do items that belong to neither set go?
Outside the circles, inside the rectangle that represents everything being considered (the universal set).
How do I fill in a 3-circle Venn diagram from numbers?
Start in the centre with the count in all three sets, then fill each pairwise overlap by subtracting the centre, then each “only” region by subtracting everything already placed in that circle.