- Fill in n (total items), and r (items chosen). Each control is labeled; you do not need to paste a JSON blob.
- Click "Run" to run the tool in your browser.
- Read the result below the form and copy it if you need it in another app.
Combination Calculator
The Combination Calculator calculates the number of combinations of selecting 'r' items...
Configuration for this calculator is missing.
How to Use This Tool
Learn More About Combination Calculator
Understanding Combinations
A combination is a selection of objects without regard to order. The number of combinations of 'n' objects taken 'r' at a time is denoted as nCr.
Combination Formula
nCr = n! / (r! * (n - r)!)
Example
If you have 5 items and want to select 3 without regard to order, the number of combinations is 5C3 = 5! / (3! * 2!) = 10.
About
The Combination Calculator calculates the number of combinations of selecting 'r' items from a set of 'n' items, where the order of selection does not matter. It uses the formula nCr = n! / (r! * (n-r)!).
Examples
Valid n=5, r=2
Input
Input
{
"n": 5,
"r": 2
}Output
10
Valid n=10, r=3
Input
Input
{
"n": 10,
"r": 3
}Output
120
Use Cases
- Determining the number of possible groups or subsets.
- Calculating probabilities in situations where order does not matter.
- Solving combinatorial problems.
- Used in statistics and probability theory.