Stirling's approximation


Definition: For large values of n, n! ≈ (n/e)n √(2nπ).

See also factorial, gamma function.

Note: This approximation is taken directly from Stirling's formula.

Author: PEB

More information

Peter Luschny lists and evaluates many approximation formulas for n!. See Eric W. Weisstein, Stirling's Approximation for a derivation and other approximations.

Go to the Dictionary of Algorithms and Data Structures home page.

If you have suggestions, corrections, or comments, please get in touch with Paul Black.

Entry modified 5 August 2021.
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Cite this as:
Paul E. Black, "Stirling's approximation", in Dictionary of Algorithms and Data Structures [online], Paul E. Black, ed. 5 August 2021. (accessed TODAY) Available from: