Logarithm Calculator
Calculate the logarithm of a positive value for a chosen base.
Calculations run in this browser. Values are not submitted to the server.
Result
Formula and assumptions
log_base(value) = ln(value) ÷ ln(base). Value must be positive; base must be positive and not 1.
Example values are shown in the input placeholders. Results use browser number precision unless the tool uses exact integer arithmetic. Check units and assumptions before using a result.