Math
Logarithm Calculator
Find the logarithm of a number to a chosen base, the exponent that the base must be raised to.
Formula
Logarithm base b of x is the exponent y such that b raised to y equals x.
How it works
Enter a positive number and a positive base other than 1. The calculator divides natural logs to change base. For example, log base 10 of 100 is 2.
FAQs
What does the Logarithm do?
It takes the values you enter and works out the logarithm for you, showing the result straight away.
What should I enter?
Enter ordinary numbers in the boxes above. If a value does not make sense for this calculation, the page will ask you to check it instead of showing a wrong answer.
Can I use the result for homework or everyday maths?
Yes. It is a general-purpose maths helper; for exam or professional work, still check the steps against your own working.