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Logarithm Calculator

Logarithm of a number in any base, plus natural and base-10 logs.

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The formula

log_b(x) = ln(x) / ln(b)

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Frequently asked questions

What is a logarithm?+
A logarithm answers "to what power must the base be raised to get this number?" For example log₁₀(1000) = 3.
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