# Log Calculator

### Logarithm Calculator

 Please enter the base (b) and a positive number (n) to calculate logbn: The base  = ? Result: The base 10 logarithm of 100 is 2 or log10100 = 2. Notes: i) e and pi are accepted values. ii) 1.2 x 103 should be entered as 1.2e3 andiii) 1.2 x 10-3 as 1.2e-3

Here is the answer to questions like: what is the base 10 log of 100? or what is the base 10 log of 100?

Use our | Log10 calculator to find the logarithm of any positive number for any number base you enter.

## What is logarithm?

A logarithm is the power to which a number must be raised in order to get some other number. In other words, the logarithm tells us how many of one number should be multiplied to get another number.

For example:

• The base 2 logarithm of 4 is 2, because 2 raised to the power of 2 is 4:
• log3 9 = 2, because 32 = 9

This is an example of a base-3 logarithm. We call it a base-3 logarithm because 3 is the number that is raised to a power.

The most common logarithms are natural logarithms and base 10 logarithms. There are special notations for them:

• A base 10 log is written simply log.
• A natural logarithm is written simply as ln.

So, the notation log alone means base ten logarithm and notation ln, means natural log.

## Basic Log Rules

• logb(x·y) = logb(x) + logb(y)
• logb(x/y) = logb(x) - logb(y)
• logb(xy) = y·logb(x)
• logb(x) = logk(x)/logk(b)

## What is logarithm and how it works

If you want to learn the basic concept of logarithms and its basic operation, you should try to watch this simple video: Logarithms Explained and Rules of Logarithms