Combinations with Repetition Calculator
Count combinations when repetition is allowed.
When you can pick the same item more than once, use combinations with repetition.
The math behind it
The count is C(n + r - 1, r), the 'stars and bars' formula.
Worked example
Choosing 3 from 5 with repetition gives 35.
FAQ
When does repetition apply?
When items can be selected multiple times, like scoops of ice cream flavors.