--- layout: "functions" page_title: "log - Functions - Configuration Language" sidebar_current: "docs-funcs-numeric-log" description: |- The log function returns the logarithm of a given number in a given base. --- # `log` Function `log` returns the logarithm of a given number in a given base. ```hcl log(number, base) ``` ## Examples ``` > log(50, 10) 1.6989700043360185 > log(16, 2) 4 ``` `log` and `ceil` can be used together to find the minimum number of binary digits required to represent a given number of distinct values: ``` > ceil(log(15, 2)) 4 > ceil(log(16, 2)) 4 > ceil(log(17, 2)) 5 ```