Logarithm Calculator
Logarithm in any base, including log and ln.
What is a logarithm calculator?
A logarithm calculator finds the power to which a base must be raised to get a number. Example: log10(100) = 2, because 10² = 100.
How to use it
Enter a number, choose base 10, base e or base 2, then tap Calculate Log.
Formula
log base b of x is the power y such that b^y = x. For base 10, log10(100) = 2 because 10² = 100. The natural log ln uses base e (about 2.718), and ln(e) = 1.
Example
Log asks: to what power must 10 be raised to get 100? 10² = 100, so log10(100) = 2. Similarly, log10(1000) = 3 because 10³ = 1000, and log2(8) = 3 because 2³ = 8.
Frequently Asked Questions
What is log10(100)?
2.
What is ln(e)?
1.
Can I take the log of 0 or a negative number?
No, the number must be greater than 0.
More calculators: Math Tools and All Tools.