COMBIN in Collabora Office: Choose Items Without Counting Their Order

• Introduced: documented by Collabora Office 26.04; the original introduction release is not established.
• Availability: COMBIN is documented in the official 26.04 Calc Help.
• Scope: desktop Calc documentation; separately deployed Online and mobile versions have not been verified.
• Checked: October 13, 2026, against the official COMBIN reference. Documentation check; not a native application test. Expected examples are independently calculated.

=COMBIN(total_items; items_chosen)

The first count describes the pool of distinct items; the second describes how many are selected. For the examples here, both are whole numbers with 0 <= items_chosen <= total_items.

The official Collabora reference supplies the factorial formula and the example AB, AC, BC when selecting two of A, B and C. One sentence in that Help section uses the word “ordered,” but its example and factorial definition count unordered selections: AB and BA are the same selection. This guide follows that mathematical definition and explicit example.

=COMBIN(4;2)

Expected result: 6. For the set A, B, C, D, the possible pairs are AB, AC, AD, BC, BD and CD. Writing the pairs out is an effective independent check of what is being counted.

There are no AA or BB pairs because repetition is not allowed. There are no separate BA or CA entries because order does not distinguish a selection.

Enter 8 in B2 for the number of distinct candidates and 3 in C2 for the number of places.

=COMBIN(B2;C2)

Expected result: 56. This is the count of possible three-person groups if every candidate is eligible and every group is allowed.

It does not assign different roles. If the three places are president, secretary and treasurer, selecting the same three people in different roles produces different outcomes. That is an ordered-assignment question and requires a different counting model.

For the same eight-item, three-chosen case:

=FACT(8)/(FACT(3)*FACT(8-3))

Expected result: 56. The numerator is 40320; the denominator is 6×120 = 720; 40320/720 is 56.

This is useful as a small-input verification. It is not a recommendation to replace COMBIN with very large intermediate factorials, which can exceed numerical limits before the final mathematical value becomes useful.

=COMBIN(8;3)
=COMBIN(8;5)

Both are expected to return 56. Choosing which three are included is equivalent to choosing which five are excluded. This symmetry is a valuable cross-check when the intended population is fixed.

For boundary cases, choosing none of five items or choosing all five gives one possible selection in each case. The interpretation is one empty selection or one complete selection, not zero selections.

A menu has five distinct starters and four distinct desserts. If a selection contains two starters and one dessert, and every combination is permitted:

=COMBIN(5;2)*COMBIN(4;1)

Expected result: 40. There are ten starter pairs and four dessert choices for each pair.

Multiplication assumes the choices are independent. Dietary restrictions, package rules or incompatible pairings can invalidate that assumption. A numerical result remains easy to obtain even when it no longer counts the actual allowed set.

Before writing a formula, answer two questions: may an item be selected more than once, and does position/order distinguish outcomes? COMBIN covers “no” for both.

A four-digit code, for example, may allow repeated digits and treats 1234 as different from 4321; plain COMBIN is unsuitable. An unranked committee chosen from distinct eligible people is closer to the COMBIN model.

The similarly named COMBINA permits repetition under its own definition. Do not substitute it solely to make an invalid count calculate.

Use nonnegative integer counts in the stated domain. Fractional counts, negative counts or a request to choose more items than exist should be investigated before the result is interpreted. Their exact coercion and error presentation have not been native-tested for this guide.

Large combinatorial counts may exceed exact integer representation in a spreadsheet. Formatting more digits does not establish exactness. For a critical large-count calculation, independently verify the mathematical count and the application’s numeric behavior.

A native test should record the Collabora build and verify the explicit six pairs, the value 56, its complement symmetry and the 40-category example. No target-application execution was performed; the expected results are independent integer arithmetic against the product’s documented formula.

• Collabora Office 26.04: COMBIN, checked October 13, 2026.
• Editorial standards.