13 Choose 5

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

What is 13 choose 5?

Answer

13 choose 5 is
1,287

Order doesn't matter, no repeats: 1,287 ways to choose 5 of 13 items.

C(13, 5) = 13! / (5! · 8!)

= (13 × 12 × 11 × 10 × 9) / (5 × 4 × 3 × 2 × 1)
= 154,440 / 120

= 1,287

If order matters (permutations): P(13, 5) = 13 × 12 × 11 × 10 × 9 = 154,440 — each combination in 5! = 120 orders.

Row 13 of Pascal's triangle
k13 choose k
01
113
278
3286
4715
51,287
61,716
71,716
81,287
9715
10286
1178
1213
131

Row sum: 213 = 8,192 — all subsets of 13 items.

See Also

FAQ

What is 13 choose 5?

13 choose 5 is 1,287

Why is 13 choose 5 the same as 13 choose 8?

Every way to choose 5 of 13 items leaves exactly 8 behind, so choosing 5 and choosing which 8 to leave out are the same count: 13 choose 5 = 13 choose 8 = 1,287. In the formula n! / (k! (n − k)!) the two factorials below just swap places.

How many ways are there if order matters?

P(13, 5) = 154,440. Each of the 1,287 combinations can be put in order in 5! = 120 ways, so permutations = combinations × k!: P(n, k) = n! / (n − k)!.