The LOG function returns the logarithm of a number to the base you specify.

This function is the inverse of the POWER function.

For example, if the formula POWER(a, b) gives a result of c, the formula LOG(c, a) gives a result of b.

LOG(Number, Base)

ArgumentData typeDescription
NumberNumberThe number to return the logarithm of.
Base (optional)Number

The base to apply when returning the logarithm.

If omitted, the LOG function uses a default base of 10.

In Polaris, the LOG function returns a value of NaN (Not a Number) if you use positive infinity for the Base argument.

In the Classic Engine, the LOG function returns 0 if you use positive infinity for the Base argument.


In this example, the Number and Base line items each contain four numeric values to be used for the Number and Base arguments respectively. The other two line items contain formulas to calculate the logarithm for the numbers.

As the formula for the Logarithm base 10 line item does not contain the Base argument, the function returns the base 10 logarithm by default.

The values in this example are rounded to eight significant digits. You can change the number of digits that display in Anaplan under Format in blueprint view.

Item 1Item 2Item 3Item 4

Logarithm with various bases

LOG(Number, Base)



Logarithm base 10