Logarithm Calculator

Understanding Logarithms

A logarithm is the power to which a number (the base) must be raised to produce another number. For example, the logarithm of 100 to base 10 is 2, because 10² = 100. This is written as log₁₀(100) = 2.

The Equation: log_b(x) = y

• b is the base of the logarithm. It must be a positive number and not equal to 1.
• x is the value or argument of the logarithm. It must be a positive number.
• y is the result, which is the exponent to which the base is raised.

How to Use the Calculator

This calculator can solve for any of the three variables (b, x, or y) as long as you provide the other two. Leave the field you want to calculate empty.

• To find y (the result): Enter the base (b) and the value (x).
• To find x (the value): Enter the base (b) and the result (y).
• To find b (the base): Enter the value (x) and the result (y).

You can use 'e' for the natural logarithm base.