Google Sheets Function

LOG

Returns the logarithm of a number to a specified base.

Generate a formula with AI Same function in Excel

This function works the same in Google Sheets as it does in Excel — same syntax and arguments.

Syntax

LOG(number, [base])

The LOG function calculates the logarithm of a positive number based on a provided base. If the base argument is omitted, Excel defaults to a base of 10.

Arguments

numberrequiredThe positive real number for which you want the logarithm.
baseoptionalThe base of the logarithm; if omitted, it defaults to 10.

Examples

=LOG(100, 10)

Result: 2

Calculates the base-10 logarithm of 100, which is 2.

=LOG(8, 2)

Result: 3

Calculates the base-2 logarithm of 8, which is 3.

FAQ

What happens if the number is zero or negative?

The function will return a #NUM! error because logarithms are only defined for positive numbers.

Related functions

LN LOG10 POWER