Choose Calculator nCr Enter a number n and number r into the choose calculator. Here are the steps to follow when using this combination formula calculator. Where n number of items.
Where n number of items.
NCr n r. Combinations nCr are the number of combinations of numbers that can be put together where the order that they are selected doesnt matter and numbers are not repeated. The formula to determine the number of possible combinations is as follows. N C r n.