Wauvel

Excel like a finance pro.

← The library

Statistical function

GAMMA

Returns the gamma function value.

Rarely usedDifficulty 1500 · AdvancedUsage rank #397 of 520
Practice · 2 questions →

When to use it

The gamma function, which extends the factorial to non-integers: GAMMA(n) = (n-1)!.

The shape of it

Syntax
=GAMMA(number)

Worked examples

  • Integer

    =GAMMA(5) 24

    Four factorial.

  • Half

    =GAMMA(0.5) 1.772453851

    The square root of pi.

  • Non-integer

    =GAMMA(2.5) 1.329340388

    A non-integer value.

Worth knowing

  • GAMMALN is safer for large arguments because it does not overflow.
  • Appears in the normalizing constants of the gamma, beta, and t distributions.
  • GAMMA(n+1) equals FACT(n).

Where it goes wrong

  • #NUM! for 0 or negative integers.
  • Overflows to #NUM! above about 171.6.

Related

Learn the moves here — or let Wauvel run them on your numbers.

Meet your AI CFO →

One CFO-grade Excel tip a week

A short, practical email for finance operators — functions, shortcuts, and the moves that save an afternoon. Free, unsubscribe anytime.