12 Choose 12

Combination Calculator
Total items (n)
Items chosen (k)

What is 12 choose 12?

Answer

12 choose 12 is
1

Order doesn't matter, no repeats: 1 way to choose 12 of 12 items.

There is exactly one way: take all.

C(12, 12) = 12! / (12! · 0!)

= 1

0! = 1 (an empty product), so 12! cancels out completely.

If order matters (permutations): P(12, 12) = 12 × 11 × 10 × … × 1 = 479,001,600 — each combination in 12! = 479,001,600 orders.

Row 12 of Pascal's triangle
k12 choose k
01
112
266
3220
4495
5792
6924
7792
8495
9220
1066
1112
121

Row sum: 212 = 4,096 — all subsets of 12 items.

See Also

FAQ

What is 12 choose 12?

12 choose 12 is 1

Why is 12 choose 12 the same as 12 choose 0?

Every way to choose 12 of 12 items leaves exactly 0 behind, so choosing 12 and choosing which 0 to leave out are the same count: 12 choose 12 = 12 choose 0 = 1. In the formula n! / (k! (n − k)!) the two factorials below just swap places.

How many ways are there if order matters?

P(12, 12) = 479,001,600. The only combination — all 12 items — can be put in order in 12! = 479,001,600 ways, so permutations = combinations × k!: P(n, k) = n! / (n − k)!.