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Excel

LOG function in Excel

Returns the logarithm of a number to a specified base

=LOG(number, [base])

LOG syntax and parameters

Two arguments, one required.

  • numbernumberRequired

    The positive real number for which you want the logarithm.

  • basenumberOptional

    The base of the logarithm. If base is omitted, it is assumed to be 10.

LOG examples

Formulas you'll actually reuse.

  1. How many halvings — a base-2 logarithm:

    =LOG(B2, 2)

    Result10

  2. Base 10 when no base is given — orders of magnitude:

    =LOG(B2)

    Result5

LOG in Google Sheets

Same name — your formula ports as-is.

Try LOG in the playground

Edit the example — nothing to install.

Preloaded with the LOG formula from Example 1 — change anything and watch it respond.

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Related functions

More ways Excel gets this done.