log_b(x) is the exponent to which base b must be raised to get x: b^(log_b(x)) = x.

What bases are allowed?

Base must be positive and not 1. Value must be positive.

Online Logarithm Calculator

Calculate logarithm: log_base(value). Enter value and base to get log_base(value). Natural log (base e) when base is e or left blank.

Value

Base (e or number; blank = natural log)

What is a logarithm?: log_b(x) is the exponent to which base b must be raised to get x: b^(log_b(x)) = x.
What bases are allowed?: Base must be positive and not 1. Value must be positive.

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