How it works
Fill in the 2 fields above and Combinations with Repetition Calculator calculates the result instantly, recalculating as you change any value. It applies the formula C(n+r−1, r). The math runs locally in your browser — nothing is sent to a server.
Formula
C(n+r−1, r)Examples
- Items (n) 5, Choose (r) 3 → Combinations: 35
Frequently asked questions
How do I use the Combinations with Repetition Calculator?
Enter your values in the 2 input fields and the result is calculated automatically as you type. Change any value to see the numbers update instantly.
What formula does the Combinations with Repetition Calculator use?
It uses C(n+r−1, r). The calculation is performed in your browser using standard, well-established math for accurate results.
Is my data private?
Yes. The Combinations with Repetition Calculator runs entirely in your browser. Nothing you enter is uploaded, saved to a server, or shared — it never leaves your device.
Is the Combinations with Repetition Calculator free?
Yes, it is completely free with no sign-up, no limits and no watermarks. Like every tool on math and the rest of the platform, you can use it as often as you like.
Popular in Math
Quadratic Equation Solver
Solve ax² + bx + c = 0 for real or complex roots.
Percentage to Decimal Converter
Convert a percentage to a decimal and a fraction.
2×2 Matrix Determinant Calculator
Calculate the determinant of a 2×2 matrix.
2×2 Matrix Addition Calculator
Add two 2×2 matrices together.