Logarithm Calculator
MathematicsCalculate natural logarithms (ln), common logarithms (log₁₀), binary logarithms (log₂), and logarithms with arbitrary custom bases using the mathematical change-of-base rule.
ln(a)=6.907755 · log₁₀(a)=3
About this calculator
Logarithms quantify exponential scaling across diverse scientific fields: the Richter earthquake scale, decibels for acoustic sound pressure, pH in chemistry, and algorithmic complexity (O(log n)) in computer science.
This calculator computes logarithmic functions for any positive real argument and positive base (b ≠ 1). It displays the natural log, decimal log, binary log, and custom base evaluation alongside inverse verification via exponentiation.
How It Works & Formula
Using the fundamental change-of-base identity, log_b(a) = ln(a) / ln(b). The engine evaluates native IEEE 754 natural logarithms with double-precision accuracy, reporting errors when arguments or bases violate domain constraints (x ≤ 0 or b ≤ 0 or b = 1).
Related Calculators
View All (32)Percentage Calculator
Calculate percentage change, percentage of values, and increase/decrease discounts instantly.
Scientific Calculator
Advanced mathematical calculations with trigonometry, powers, roots, and logarithms.
Fraction Calculator
Add, subtract, multiply, and divide fractions with step-by-step simplification.
Quadratic Equation Solver
Solve ax² + bx + c = 0 with real/complex roots, discriminant, and vertex coordinates.