Log Calculator
Here is the answer to questions like: What is the base 10 logarithm of 100? or what is the base 10 log of 100?
Use the | Log10 calculator below to find the logarithm of any positive number for any number base you enter.
See also
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:
- log_{3} 9 = 2, because 3^{2} = 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
- log_{b}(x·y) = log_{b}(x) + log_{b}(y)
- log_{b}x/y) = log_{b}(x) - log_{b}(y)
- log_{b}(xy) = y·log_{b}(x)
- log_{b}(x) = log_{k}(x)/log_{k}(b)
Log Calculator
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