✓ Effortless Math · Free Tool

Factorial Calculator

Enter a non-negative integer n to compute n! exactly — see the full expansion n·(n−1)·…·1, the digit count, and a scientific-notation approximation, with step-by-step working.

n! = n · (n−1) · (n−2) · … · 2 · 1
value n ! = ?

Enter a whole number n ≥ 0. Computed exactly with BigInt, so values like 20! are precise. Capped at n = 1000 to stay fast.

Results

Factorial
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n!
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Digit count
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Scientific notation (approx.)
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Expansion
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Step-by-step