Enter any integer or numerical value into the calculator and select a base value to determine the negative log of that number.

## Negative Log Formula

The following formula is used to calculate a negative log.

x = Log_{b}(1/a)

- Where X is the negative log
- b is the base value
- a is the number the negative log is taken of

## Negative Log Definition

**What is a negative log? **A negative log is defined as the number of times required that 1 must be divided by the base in order to achieve the log number. So, -Log_{2}(.5) = 1. Since 1/2 = -.5.

## Example

**How to calculate a negative log? **Calculating the negative log is as simple as performing the normal log function on 1/x instead of x. The base stays the same. For example, the negative log of -log(10) = log(1/10) = 1.

## Negative Log FAQ

**Is a negative log the same as antilog? **In most cases, the terms negative log and antilog are used interchangeably.

**Can you calculate a negative log? **Calculating a negative log is as simple as using the formula x = Log_{b}(1/a) , where x = -log_{b}(a).