Online Logarithm Calculator

Calculate the log of any number with any base, including natural log (ln) and common log (log₁₀).

log ( )

Custom Base

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log₁₀(100)

Natural Log (ln)

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loge

Common Log

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log10

Binary Log

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log2

What is a Logarithm?

In mathematics, the logarithm is the inverse function to exponentiation. That means the logarithm of a given number x is the exponent to which another fixed number, the base b, must be raised, to produce that number x.

logb(x) = y => by = x

Common Types