Calculate logarithms in any base — log base 10 (common log), natural log (ln, base e), log base 2 (binary), or any custom base. Includes antilogarithm and change-of-base conversion.
Calculate Logarithm
Result
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log₁₀(x)
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ln(x)
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log₂(x)
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Antilog₁₀
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Enter a number above
All common logarithm bases calculated simultaneously.
Frequently Asked Questions
What is a logarithm?
A logarithm asks: "to what power must the base be raised to get x?" So log₁₀(1000) = 3 because 10³ = 1000. log_b(x) = y means b^y = x.
What is the natural logarithm (ln)?
The natural log uses base e (≈2.71828). It appears throughout calculus, exponential growth/decay, and probability. ln(e) = 1, ln(1) = 0.