What is the difference between combinations and permutations in Excel?

Combinations and permutations both count how many ways you can choose items from a group, but they answer different questions. Permutations count arrangements where order matters; combinations count selections where order does not. In Excel you calculate them with separate functions — PERMUT and COMBIN (plus PERMUTATIONA and COMBINA when repetition is allowed) — and the choice between them depends entirely on whether swapping two chosen items produces a different result.

The core distinction: does order matter?

Ask one question before picking a function: if I rearrange the same items, is that a new outcome?

• Order matters → permutation. Example: a 3-digit lock code. 1-2-3 and 3-2-1 are different codes.
• Order doesn't matter → combination. Example: a 3-person committee drawn from 10 people. The same three people form the same committee no matter what order you list them.

A second question decides which variant you need: can an item be chosen more than once?

Excel functions for each case

PERMUT — ordered, no repeats

=PERMUT(number, number_chosen) returns the number of ordered arrangements of number_chosen items taken from number distinct items, with no item used twice.

Example: how many ways can 3 runners finish first, second, and third out of 8?

=PERMUT(8,3)   → 336

Each finishing order is a distinct outcome, and a runner can't hold two places.

COMBIN — unordered, no repeats

=COMBIN(number, number_chosen) returns the number of ways to choose number_chosen items from number items when order is irrelevant.

Example: how many 5-card hands can be dealt from a 52-card deck?

=COMBIN(52,5)   → 2,598,960

A hand is the same set of cards regardless of the order dealt.

PERMUTATIONA and COMBINA — repetition allowed

These variants allow an item to be picked again.

• =PERMUTATIONA(10,3) → 1000. This is the count of 3-character codes from 10 symbols where repeats are allowed (10 × 10 × 10).
• =COMBINA(n,k) counts unordered selections where repeats are permitted.

Use these when the same value can appear more than once in a result — for example, a password that may repeat a character, or a lottery format that allows a number to recur.

A worked comparison

Suppose you have 5 distinct items and you choose 2.

• Ordered, no repeats (PERMUT): =PERMUT(5,2) → 20
• Unordered, no repeats (COMBIN): =COMBIN(5,2) → 10

The permutation count is exactly double the combination count here, because each unordered pair can be arranged in 2 orders. That relationship is general: PERMUT(n,k) = COMBIN(n,k) × FACT(k), where FACT(k) is the number of ways to order the k chosen items.

When to use which

• Passwords, PINs, lock codes, race finishes, seating in assigned seats → order matters → PERMUT / PERMUTATIONA.
• Lottery draws, card hands, committees, teams, choosing toppings → order doesn't matter → COMBIN / COMBINA.
• Repetition allowed (a digit or symbol can repeat) → the ...A variants.

Common pitfalls

• Using COMBIN when order matters undercounts by a factor of FACT(k). If your answer looks too small by exactly that factor, you likely picked the wrong function.
• Forgetting the repetition question. PERMUT and COMBIN assume no repeats; if repeats are allowed, your result will be too low.
• Confusing the arguments. Both functions take (number, number_chosen) — the total pool first, then how many you pick.
• Non-integer or negative inputs return errors, since these functions count discrete selections.

Exceljet's own coverage groups these under counting and probability formulas, alongside related functions like FACT, and its featured formulas show the same pattern of building a count from a clear rule about order and repetition. Once you've settled those two questions, the function choice follows directly.