Logarithm Calculator

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On this page is a logarithm calculator. Enter a logarithm base and x, and we'll compute the logarithm.

This calculator can compute logs of base 2, e, and 10. However, for a dedicated calculator please try:

Logarithm Calculator

What is a Logarithm?

A logarithm is an argument x where you have to find a power y to raise x by to equal. Rewritten, it means "how many times do I have to raise a number to equal a second number?". Stated in context, log base 2 of 64 means "What power do I raise 2 to if I want to equal 64?".

A logarithm is the opposite of an exponent. If you knew a base and an exponent, you'd be able to compute a result. When finding a logarithm, you know the base and the result and the logarithm is the exponent value you are looking to find.

Logarithm Formula

The formula for a logarithm is:



  • b: the base of the equation (the number we need to raise to get the result)
  • x: the argument; the number we need to raise b^y to equal
  • y: the exponent or power; the number we need to raise the base to equal

Logarithm Example

For example, let's say you wanted to find the log base 2 of 64. Here's how it'd look:

\log_2(64)\ or\ 2^y=64\\y=6

In this case you need to raise 2 to the 6th power to get 64.

Using the Logarithm Calculator

You only need to enter two numbers to get the logarithm: the base b and the argument x. Enter those to match the "log base b of x" sentence form. For base e you can type in the letter 'e' or try the natural logarithm calculator.

When happy with your input, hit Compute Logarithm.

Afterwards, visit our other tools and calculators.



PK started DQYDJ in 2009 to research and discuss finance and investing and help answer financial questions. He's expanded DQYDJ to build visualizations, calculators, and interactive tools.

PK is in his mid-30s and works and lives in the Bay Area with his wife, two kids, and dog.

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