Venn diagram maker

The trick is transparency. Set the circles to part opacity and the overlaps appear on their own, in a colour that belongs to both.

When a Venn diagram is the clearest way

• Comparing two or three options and showing the shared ground
• Teaching sets, logic and classification
• Positioning: what you do that others do not
• Any slide where the point is an intersection

The mistake worth avoiding: a fourth circle

Two circles show every combination of two sets, and three circles show every combination of three. Four circles cannot: with four round circles, some of the sixteen possible combinations have no region at all, so the diagram quietly leaves cases out.

If you need four sets, use four ellipses arranged so every overlap exists, or switch to a table. More often, the honest answer is that a comparison of four things is clearer as a grid of ticks than as any diagram.

Making one that reads well

Two or three circles

Four gets unreadable fast, because a proper four-set Venn cannot be drawn with circles at all.

Opacity, not layering

Part-transparent fills give you overlap colours for free and let every label stay visible.

Label outside the overlap

Set names go in the part of the circle that belongs only to that set.

Size does not mean quantity

Unless you are drawing a proportional diagram, do not let readers infer size from area. Say the numbers if they matter.

Drawing the circles

1. Open the template, which has three circles already overlapping.
2. Drag a circle to change how much it overlaps the others.
3. Set each circle's opacity to about 60% in the right-hand panel so the overlaps show through.
4. Put each set's label at the top of its own circle, clear of the overlaps.
5. Add a text shape in each overlap for what belongs to both.
6. Export a PNG with a transparent background if it is going onto a coloured slide.

Venn diagram questions