# Log (Logarithm) Online Calculator

command: log

log returns the log of the given value. Default base is e (Napier's number or Euler's number). Try to input log 4 in the header form.

output:

log 4
log
(4) = 1.3862943611198906


1.3862943611198906 is log(4).

## Multiple arguments

log can return the logs of arguments like that:

log 2 2.7 5 100


output:

log 2 2.7 5 100
log
(2) = 0.6931471805599453
(2.7) = 0.9932517730102834
(5) = 1.6094379124341003
(100) = 4.605170185988092


## Base

Default base is e and you can change the base using the hyphen-argument.

input:

log -b=2 4 8 16 32 64


output:

log 4 8 16 32 64
log
(4) = 2.0
(8) = 3.0
(16) = 4.0
(32) = 5.0
(64) = 6.0


-b is the argument meaning the log base, and -b=2 means the base of log function is 2.

Let's see the another example.

input:

log -b=10 100 1000 0.1 0.001


output:

log 100 1000 0.1 0.001
log
(100) = 2.0
(1000) = 3.0
(0.1) = -1.0
(0.001) = -3.0


## Base 2

The log function with base 2 can be expressed as log2.

input:

log2 4 8


output:

log2 4 8
log2
(4) = 2.0
(8) = 3.0


log2 command is completely equal to the command log -b=2.

## Base 10

The log function with base 10 can be expressed as log10.

log10 100 1000 1


output:

log10 100 1000 1
log10
(100) = 2.0
(1000) = 3.0
(1) = 0.0


log10 command is completely equal to the command log -b=10.

## Note

The hyphen-argument should not have the space and the next expressions are invalid.

-b =2
-b = 2
- b=2


-b =2 can be regarded by the calculator as the pair of -b and 2.