Build a 3-circle Venn diagram by entering your set labels, individual counts, and intersection values. Fill in Set A, Set B, and Set C along with their pairwise overlaps and the center intersection — the diagram updates to show each region's size and your total population at a glance.
Total Items (Union)
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Set A Total
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Set B Total
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Set C Total
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A ∩ B (incl. center)
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A ∩ C (incl. center)
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B ∩ C (incl. center)
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A Venn diagram uses overlapping circles to show the logical relationships between different sets or groups. Each circle represents a set, and overlapping areas show items shared between those sets. They are widely used in statistics, logic, mathematics, and everyday comparisons.
Each intersection field should contain only the count exclusive to that specific overlap zone. For example, 'A ∩ B Only' should hold items in both A and B but NOT in C. The center field 'A ∩ B ∩ C' holds items belonging to all three sets simultaneously.
A Venn diagram always draws all possible intersecting circles regardless of whether those intersections contain any items, even if some regions are empty. An Euler diagram only draws regions that actually contain elements, making it more visually concise but potentially less informative about logical possibilities.
The union is the total number of unique items across all three sets combined. It equals the sum of all seven distinct regions: A only, B only, C only, A∩B only, A∩C only, B∩C only, and the center A∩B∩C. Each item is counted once regardless of how many sets it belongs to.
Set A Total is the full count of items in Set A, including those it shares with other sets. It is calculated as: A Only + A∩B Only + A∩C Only + A∩B∩C. The same logic applies to Sets B and C.
This generator works with counts (numbers of items per region). If you have a list of named items, count how many belong to each region and enter those numbers. The labels let you describe what each set represents — for example 'Python developers', 'Project A members', or 'Biology students'.
Simply enter 0 for the intersection field between those two sets. The calculator will still compute the union and individual set totals correctly, and the bar chart will show that region as empty.
Each percentage shows what fraction of the total union that specific region represents. For example, if the center region has 5 items out of a total of 105, it represents approximately 4.76% of all unique items across the three sets.