The natural logarithm is log base e, where e ≈ 2.718. ln(x) is the power to which e must be raised to get x.

Why must x be positive?

Logarithms of non-positive numbers are not defined in the reals.

Online Natural Log Calculator

Calculate the natural logarithm ln(x) for any positive number.

x (positive number)

What is ln(x)?: The natural logarithm is log base e, where e ≈ 2.718. ln(x) is the power to which e must be raised to get x.
Why must x be positive?: Logarithms of non-positive numbers are not defined in the reals.
What is ln(1)?: ln(1) = 0, because e^0 = 1.

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