Maths & numbers
Logarithm calculator
Calculate a logarithm in a chosen positive base.
A clear answer. Here’s how.
log base b of x = ln(x)/ln(b). The value and base must be positive, and the base cannot equal 1. Also shows the natural and base-10 logarithms of the input.
See a worked example
Worked example
A fixed demonstration, separate from the values you enter above.
- Positive value
- 100
- Logarithm base
- 10
Example result
- Logarithm in chosen base
- 2
- Natural logarithm
- 4.60517018599
- Base-10 logarithm
- 2