Logarithm calculator
Find the power of a base that gives your value.
Formula
log_b(x) = ln(x) / ln(b)
Logarithm ≈ ln((100))÷ln((10))
How to use
- Enter a positive value x.
- Enter a positive base other than 1.
- Read the logarithm.
Examples
- log₁₀(100) = 2.
- log₂(8) = 3.
Frequently asked questions
Why is base 1 invalid?
Every power of 1 equals 1, so it cannot define a logarithm.
Can the base be below 1?
Yes, as long as it is positive. For example, log base 0.5 of 8 is −3.
Can the value be negative or zero?
No. This tool computes real logarithms of positive values only.
Sources
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