㏑
Logarithm Calculator
Natural and common logarithms
logarithmlnlognatural log
📖 How to Use
- Enter a positive number
- Optionally enter a custom base
- Click Calculate to see ln, log₁₀, log₂, and custom-base logarithms
📐 Formula
ln(x) = logₑ(x) log₁₀(x) = log(x) logₐ(x) = ln(x)/ln(a)
❓ FAQ
What happens if I enter a negative number?▾
Logarithms require positive inputs. A negative number will show an error message.
🔗 Related Calculators
%½ⁿ🔬➗
Percentage Calculator
Calculate percentages, percentage change, and difference
Fraction Calculator
Add, subtract, multiply, and divide fractions
Exponent Calculator
Powers and roots
Scientific Calculator
Trigonometry, logarithms, exponents and more
Prime Factorization
Decompose integers into prime factors
About Logarithm Calculator
This tool is completely free, no registration required. Works directly in your browser. Supports both PC and mobile devices.
Logarithm Calculator is a free online tool that works on both PC and mobile. No registration or download required — just open in your browser. Results are accurate and reliable for everyday use and professional reference.