COMBIN

COMBIN is a DAX function that returns the number of combinations for a given number of items, useful for determining the total possible number of groups for a given set of items.

Syntax

COMBIN(
   Number,
   Number_chosen
)

Argument	Properties	Description
Number		The number of items.
Number_chosen		The number of items in each combination.

Return Values

Returns the number of combinations for a given number of items.

Remarks

• Numeric arguments are truncated to integers.

• If either argument is nonnumeric, COMBIN returns the #VALUE! error value.

• If number < 0, number_chosen < 0, or number < number_chosen, COMBIN returns the #NUM! error value.

• A combination is any set or subset of items, regardless of their internal order. Combinations are distinct from permutations, for which the internal order is significant.

• The number of combinations is as follows, where number = $n$ and number_chosen = $k$:

  $$(\genfrac{}{}{0ex}{}{n}{k})=\frac{P_{k,n}}{k!}=\frac{n!}{k!(n-k)!}$$

  Where

  $$P_{k,n}=\frac{n!}{(n-k)!}$$

• This function is not supported for use in DirectQuery mode when used in calculated columns or row-level security (RLS) rules.

Formula	Description	Result
= COMBIN(8,2)	Possible two-person teams that can be formed from 8 candidates.	28

Contribute » | Contributors: Rick de Groot
Microsoft documentation: https://learn.microsoft.com/en-us/dax/combin-function-dax