How does the Derangements Calculator work?

Identify number of items (n) Then: Calculate factorial of n Then: Apply derangement formula Then: Use for seat arrangement, gift exchange problems.

Can you give an example of how to use the Derangements Calculator?

Example: Input n = 4 gives a result of D(4) = 9 (Number of ways 4 people can exchange gifts so nobody gets theirs).

Is the Derangements Calculator free to use?

Yes — completely free with no registration, download, or subscription required. All calculations happen instantly in your browser.

How accurate is the Derangements Calculator?

Our Derangements Calculator uses verified mathematical formulas and is accurate to multiple decimal places. Results are calculated in real-time using the same methods used by professionals.

Mathématiques

Derangements Calculator

Calculates derangements (permutations with no fixed points).

Difficulty:advanced

References

›Derangements Calculator — Wikipedia

🔒

100% Gratuit

Sans inscription

✓

Précis

Formules vérifiées

⚡

Instantané

Résultats immédiats

📱

Compatible mobile

Tous les appareils

Derangements Calculator

Qu'est-ce que Derangements Calculator?

Formule

Comment Derangements Calculator

Exemples résolus

Erreurs courantes à éviter

Paramètres