Math Calculators

Combination Calculator

Count unordered selections. The estimate updates in your browser as you type.

Combinations 120

Local estimate.

What this tool is for

Combination Calculator is built for math checking inside math calculators when you need to counts unordered selections. It focuses on combination instead of making you adapt a broad calculator to a narrow task.

When to use it

Use it when items and chosen are already known and you want a fast estimate before comparing options, checking a worksheet, or copying the result into another workflow.

Inputs

  • Items is the count that the result is divided by, multiplied by, or compared against.
  • Chosen is one of the direct inputs used to calculate combination.

Formula

nCr = n! / (r! x (n - r)!)

Example

10C3 = 120.

What the result means

The result labeled "Combination" is the direct output of nCr = n! / (r! x (n - r)!). In the worked example, 10C3 = 120.

Before you rely on the result

Check the inputs and formula before using the result in homework, engineering, finance, or scientific work.