How this calculator works
Calculate logarithms for any valid base and positive value.
Formula
log_b(x) = ln(x) / ln(b)
Step-by-step
- Enter value x (must be greater than 0).
- Enter base b (must be greater than 0 and not 1).
- Calculate to get the logarithm result.
Example
- x = 1000
- b = 10
log_10(1000) = 3
FAQs
Why can't base equal 1?
Because powers of 1 are always 1, so logarithm with base 1 is undefined.
Can base be e?
Yes. For natural logarithm use base approximately 2.718281828.