Combination Calculator (nCr)
Count the combinations of r items chosen from n, where order doesn't matter.
Change the values and press Calculate to work out your own figures.
Enter the number of objects and how many are chosen.
Show the working
- nPr = n! ÷ (n − r)! = 10! ÷ 7! = 720
- nCr = n! ÷ (r! (n − r)!) = 120
How to use it
Enter the number of objects and how many are chosen.
Probabilities can be typed as decimals, fractions or percentages. Show the working gives the formula with your numbers in it.
Key facts
nCr = n! ÷ (r! (n − r)!)
Poker hands
There are 2,598,960 five-card hands from a 52-card deck: 52C5.
Questions
What is 10 choose 3?
120.
What is nC0?
1: there is one way to choose nothing.
Formulas
nCr = n! ÷ (r! (n − r)!)
Sources
Limitations
- Probabilities can be typed as decimals (0.25), fractions (1/4) or percentages (25%).