CalcReal

Logarithm Calculator

Calculate log base N of X. Supports common log, natural log, and custom bases.

How It Works

A logarithm answers the question: "To what power must the base be raised to get X?"

log_b(X) = Y means b^Y = X

The change of base formula is used for arbitrary bases: log_b(X) = ln(X) / ln(b)

Common log (log10): log10(1000) = 3, because 10^3 = 1000.

Natural log (ln): Uses base e (approximately 2.71828). ln(e) = 1.

Binary log (log2): log2(8) = 3, because 2^3 = 8.

The logarithm is only defined for positive values of X. The base must be positive and not equal to 1.

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