Permutations, combinations, and counting principle calculators. Browse our free statistics & probability tools below — all calculators are instant, accurate, and require no sign-up.
Fundamental Counting Principle Calculator — Apply the multiplication principle for multi-stage counting problems, connect to permutations, and visualize the tree diagram structure.
Permutation & Combination Calculator — Calculate P(n,r) and C(n,r), with and without repetition, compare all four variants, visualize Pascal's triangle, and explore the computation table.