Math

Logarithm Calculator

Calculate logarithms with any base. Supports natural log (ln), common log (log₁₀), binary log (log₂), and custom base.

Logarithm Calculator - Natural, Common & Custom Base

Calculate logarithms instantly with our comprehensive calculator. Find ln (natural log), log10 (common log), log2 (binary log), or logarithm with any custom base. Perfect for mathematics, science, and engineering.

What is a Logarithm?

A logarithm is the inverse operation of exponentiation. log_b(x) = y means b^y = x. For example, log10(100) = 2 because 10^2 = 100. Common types include natural log (ln, base e ≈ 2.718), common log (log10), and binary log (log2). Logarithms are essential in science, engineering, and finance.

Logarithm Change of Base

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

How to Use This Calculator

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Logarithm Calculator Applications

Exponential Growth/Decay

Solve for time in compound interest and population models.

Decibel Calculations

Sound intensity uses logarithmic scale (dB = 10×log10).

pH Chemistry

Calculate pH = -log10[H+] for acid-base chemistry.

Computer Science

Binary logarithms for algorithm complexity analysis.

Frequently Asked Questions

ln (natural log) uses base e ≈ 2.71828, while log (common log) uses base 10. In some contexts, 'log' without a base can mean natural log, but in calculators and most applications, log means base 10.