๐Ÿ“‰ Logarithm Calculator

log_10(100)2
ln(100)4.60517019

Enter a value x and a base, and this tool calculates the logarithm log_base(x). It also shows the natural logarithm (ln) at the same time. Useful for math homework or for understanding exponential changes like pH, decibels, or earthquake magnitude.

How to use

  1. Enter a value x (a positive number).
  2. Enter a base (a positive number other than 1).
  3. The logarithm with your chosen base, plus the natural logarithm (ln), are calculated automatically.

FAQ

How do I calculate a common logarithm (logโ‚โ‚€)?

Enter 10 as the base โ€” that's the default setting.

What is the natural logarithm (ln)?

It's the logarithm with Euler's number e (approximately 2.71828) as its base. It's always shown automatically in the result.

What happens if x or the base is 0 or negative?

Logarithms are only defined for positive numbers, so no result is shown for values of 0 or less. A base of 1 also isn't allowed.