Age calculator
Your exact age on any date, from your DOB.
Open toolCombinations calculator
Count ways to choose r items from n.
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THE QUICK GUIDE
How to use combinations calculator
Enter the labelled values, then process it. Copy or download the result.
How it works
NCr = n! ÷ (r! × (n − r)!); order does not matter.
A useful example
Total items n (0–1000): 10; Chosen items r: 3 → 120
Good to know
Use consistent units and currency. These are general calculations; verify important results.