Education & Math Tools
Logarithm Calculator
Enter a value and base to calculate the logarithm using the change-of-base formula.
log2(8) = 3
Uses the change-of-base formula: log_b(x) = ln(x) ÷ ln(b).
How to use this tool
- 1Enter the value.
- 2Enter the base.
- 3See the calculated logarithm.
Frequently asked questions
What is the change-of-base formula?+
log_b(x) = ln(x) ÷ ln(b) — it lets you compute a logarithm in any base using only natural log (or any other single log function).