Age calculator
Your exact age on any date, from your DOB.
Open toolPermutations calculator
Count ordered selections of r items from n.
Your input stays in this browser. No account needed.
THE QUICK GUIDE
How to use permutations calculator
Enter the labelled values, then process it. Copy or download the result.
How it works
NPr = n! ÷ (n − r)!; order matters.
A useful example
Total items n (0–1000): 10; Chosen items r: 3 → 720
Good to know
Use consistent units and currency. These are general calculations; verify important results.