Frequently Asked Questions
What is the difference between log and ln?
Log (common logarithm) uses base 10, while ln (natural logarithm) uses base e (approximately 2.718). Natural logs are used in calculus and science, common logs in engineering.
Can I use any base for the logarithm?
Yes, the change of base feature lets you compute logarithms with any base using the formula log_b(x) = ln(x) / ln(b).
Can I calculate the logarithm of a negative number?
Logarithms of negative numbers are undefined in the real number system. This calculator works within the real number domain and requires positive inputs.
Verified 2026 formulas