Venn Diagram Calculator

Calculate set relationships, unions, intersections, and complements using Venn diagrams

Configure Your Venn Diagram

Number of Sets

Total number of elements in the universal set

Number of elements in set A

Number of elements in set B

Known Set Relationship

Venn Diagram Results

Set Operations

A ∩ B:5
A ∪ B:35
A \ B:15
B \ A:15
A Δ B:30
Neither:15

Complements

A':30
B':30
(A ∩ B)':45
(A ∪ B)':15
(A \ B)':35
(A Δ B)':20

Formulas Used

|A ∪ B| = |A| + |B| - |A ∩ B| (Inclusion-Exclusion Principle)

|A \ B| = |A| - |A ∩ B| (Set Difference)

|A Δ B| = |A ∪ B| - |A ∩ B| (Symmetric Difference)

Set Theory Notation

Intersection

Elements in both sets

Union

Elements in either set

\

Difference

Elements in first set only

Δ

Symmetric Difference

Elements in exactly one set

'

Complement

Elements not in the set

Venn Diagram Regions

Two-Set Venn Diagram

Only A
A ∩ B
Only B
Neither A nor B

Quick Tips

Union includes all elements from both sets

Intersection includes only shared elements

Check that set sizes don't exceed the universal set

Intersection cannot be larger than either individual set

Worked Example

Problem Setup

Survey of 50 students about subject preferences:

  • • 20 students like Mathematics (Set A)
  • • 20 students like Science (Set B)
  • • 5 students like both subjects
  • • How many like exactly one subject?

Given Information:

  • |U| = 50 (total students)
  • |A| = 20 (like math)
  • |B| = 20 (like science)
  • |A ∩ B| = 5 (like both)

Solution

Calculations

1. Only Math: |A \ B| = |A| - |A ∩ B| = 20 - 5 = 15

2. Only Science: |B \ A| = |B| - |A ∩ B| = 20 - 5 = 15

3. Union: |A ∪ B| = |A| + |B| - |A ∩ B| = 20 + 20 - 5 = 35

4. Neither: |U| - |A ∪ B| = 50 - 35 = 15

Answer: 30 students like exactly one subject (15 + 15)

Understanding Venn Diagrams

What are Venn Diagrams?

Venn diagrams are visual representations used in set theory to show logical relationships between different sets. They use overlapping shapes (usually circles) to illustrate how sets intersect, unite, or differ from each other.

Key Concepts

  • Universal Set (U): Contains all possible elements
  • Intersection (∩): Elements common to multiple sets
  • Union (∪): All elements in any of the sets
  • Complement ('): Elements not in the set

Key Formulas

Inclusion-Exclusion Principle

|A ∪ B| = |A| + |B| - |A ∩ B|

For calculating union from individual sets

Set Difference

|A \ B| = |A| - |A ∩ B|

Elements in A but not in B

Symmetric Difference

|A Δ B| = |A ∪ B| - |A ∩ B|

Elements in exactly one set

Applications

Probability

Calculate probabilities of combined events

Logic & Computer Science

Boolean operations and database queries

Survey Analysis

Analyze overlapping responses and preferences