Discrete Math Calculators
Counting problems, solved exactly. Combinations and permutations with or without repetition, factorials of any size, sequences and sigma sums, modular arithmetic, set operations with Venn diagrams and truth tables for any logic expression.
17 calculators
Most used
- Combinations Calculator (nCr)Count the ways to choose r items from n when order does not matter, with exact big-number answers and the cancellation steps shown.
- Factorial Calculator (n!)Find the exact factorial of any whole number from 0 to 10,000, with its number of digits, trailing zeros and a step-by-step breakdown.
- Fibonacci CalculatorGet any Fibonacci number exactly, list a stretch of the sequence, or check whether a number belongs to it — with Lucas and custom starts too.
- Permutations Calculator (nPr)Count the ordered ways to arrange r items picked from n different items — race finishes, officer slates, codes without repeats — with exact results.
Combinations & permutations 7
- Circular Permutations CalculatorCount arrangements around a circle — guests at a round table or beads on a bracelet — where rotations, and optionally flips, are not counted twice.
- Combinations Calculator (nCr)Count the ways to choose r items from n when order does not matter, with exact big-number answers and the cancellation steps shown.
- Combinations with Replacement CalculatorCount unordered selections in which the same type can be picked again — scoops, donuts, dice faces — using the stars-and-bars formula.
- Even Permutations CalculatorCount the even permutations of n items, list them for small n, or check whether a given permutation is even using its cycles and inversions.
- Odd Permutations CalculatorCount the odd permutations of n items or test a specific permutation, with its cycle form, inversion count, fewest swaps and sign.
- Permutations Calculator (nPr)Count the ordered ways to arrange r items picked from n different items — race finishes, officer slates, codes without repeats — with exact results.
- Permutations with Replacement CalculatorCount codes and sequences in which symbols can be reused (nʳ), or the distinct arrangements of a word or set that contains identical items.
Factorials & sequences 8
- Arithmetic Sequence CalculatorGet the nth term, the sum of n terms and the explicit and recursive formulas of an arithmetic sequence, from the first term and difference or any two terms.
- Factorial Calculator (n!)Find the exact factorial of any whole number from 0 to 10,000, with its number of digits, trailing zeros and a step-by-step breakdown.
- Fibonacci CalculatorGet any Fibonacci number exactly, list a stretch of the sequence, or check whether a number belongs to it — with Lucas and custom starts too.
- Geometric Sequence CalculatorCalculate the nth term, partial sum and infinite sum of a geometric sequence from the first term and ratio or from any two known terms, with every step.
- Modular Exponentiation CalculatorCalculate a to the power b modulo m for numbers of any practical size, with the binary square-and-multiply trace, modular inverses and Euler's theorem check.
- Multifactorial CalculatorMultiply n by every k-th smaller number — n!! for k = 2, n!!! for k = 3 and beyond — with exact results and the full product shown.
- Pascal's Triangle CalculatorDraw Pascal's triangle, pull out any single row exactly, or color the entries by divisibility to reveal the patterns hidden inside it.
- Summation CalculatorEvaluate Σ sums (or Π products) of any expression in i, k or n between two limits, see the terms written out, and follow the running total term by term.
Sets & logic 2
- Set Operations CalculatorCombine two or three sets with union, intersection, difference, symmetric difference and complement, and see the result shaded on a Venn diagram.
- Truth Table GeneratorBuild the full truth table of a propositional formula, with a column for every sub-expression, tautology checks, equivalence testing and canonical forms.