Enter your sets
Example data table
| Set A | Set B | Set C | Intersection (A ∩ B ∩ C) |
|---|---|---|---|
| 1, 2, 3, 4, 5, New York | 3, 4, 5, 6, 7, "New York" | 0, 4, 5, 8, "New York" | { 4, 5, "New York" } |
Tip: Use quotes around multi-word items to keep them as one element.
Formula used
The intersection of sets collects elements common to every included set: A ∩ B = { x | x ∈ A and x ∈ B }.
For multiple sets, the calculator applies: A ∩ B ∩ C (∩ D). In multiset mode, each element appears the minimum number of times it appears across all sets.
How to use this calculator
- Paste elements into Set A and Set B. Add Set C or Set D if needed.
- Choose a delimiter mode and matching rules like case sensitivity.
- Select unique or multiset intersection, then choose sorting and output format.
- Press Calculate Intersection to view results above the form.
- Use the download buttons to export CSV or PDF reports.
FAQs
1) What separators can I use?
You can use commas, new lines, or semicolons in auto mode. You may also force new-line-only or whitespace-only splitting. Quoted phrases remain a single item.
2) What does case-sensitive matching mean?
When enabled, Apple and apple are treated as different items. When disabled, the calculator matches them as the same element after normalization.
3) What is the difference between unique and multiset intersection?
Unique mode shows each common element once. Multiset mode keeps duplicates: an element appears as many times as the smallest count across the included sets.
4) How are multi-word items handled?
Wrap items in double quotes to keep spaces inside one element, such as "New York". This works in all delimiter modes.
5) Why is my intersection empty?
At least one included set may not contain a shared element under your current rules. Try disabling case-sensitive matching, trimming extra spaces, or removing empty items.
6) Can I intersect more than two sets?
Yes. Enable Set C and Set D to intersect up to four sets. The output includes elements common to every included set, not just pairwise overlaps.
7) How does the membership check work?
Enter a query item and enable membership check. The calculator reports whether the normalized item exists in each included set, using the same case and trimming rules.
8) Are the downloads based on my latest result?
Yes. CSV and PDF exports use the most recent calculation saved in your session. Recalculate after changing inputs to refresh the downloadable reports.