Calculate the logarithm of a number with any base. Common log (base 10), natural log (base e), or custom base.
How it works
- Enter the number you want the log of.
- Choose the base (10 for common log, e for natural, or any other).
- View the result.
Frequently asked questions
What is a natural logarithm?
A logarithm with base e (≈ 2.718). Written as ln(x).
What is log without a base?
In most contexts it means base 10 (common log).
Why can't I take log of zero or negative?
Logarithms are only defined for positive numbers.