Permutation & Combination Calculator

All tools

Calculate permutations (nPr) and combinations (nCr) for n items taken r at a time, with the underlying factorials. Exact big-integer math. Free and instant.

The size of the whole set.
How many are selected (r ≤ n).
Combinations (nCr) –
Permutations (nPr) –
n! –
r! –
(n − r)! –
Permutations count ordered selections (nPr = n! ÷ (n−r)!); combinations count unordered ones (nCr = n! ÷ (r!(n−r)!)). n and r must be whole numbers with 0 ≤ r ≤ n. Very large results are shown in scientific notation.
Related Tools
Percentage Calculator

Answer every percentage question — X% of Y, what percent, percentage change, increase/decrease, tips and discounts. Free, in your browser.
Scientific Calculator

A full scientific calculator with trigonometry, logarithms, powers, roots, factorials, memory and history — in degrees or radians. Free, in your browser.
Text to Binary, Octal & Hex

Convert text to binary, octal, decimal and hexadecimal — and back again. Every field is live and editable, with delimiter, padding and uppercase options.
Fraction Calculator

Add, subtract, multiply or divide two fractions and instantly get the simplified result, plus its decimal, mixed-number and percentage forms. Free and instant.
Average Calculator

Paste a list of numbers to instantly get the mean, median, mode, range, sum, count and more. Robust parsing handles commas, spaces and new lines. Free and instant.
Standard Deviation Calculator

Enter a data set to compute the sample and population standard deviation, variance and mean. Robust parsing handles commas, spaces and new lines. Free and instant.

Add this free tool to your own website — copy and paste the code below.