In probability theory and statistics, the half-logistic distribution is a continuous probability distribution—the distribution of the absolute value of a random variable following the logistic distribution.

That is, for where Y is a logistic random variable, X is a half-logistic random variable.

The cumulative distribution function (cdf) of the half-logistic distribution is intimately related to the cdf of the logistic distribution.

Formally, if F(k) is the cdf for the logistic distribution, then G(k) = 2F(k) − 1 is the cdf of a half-logistic distribution.

Specifically, Similarly, the probability density function (pdf) of the half-logistic distribution is g(k) = 2f(k) if f(k) is the pdf of the logistic distribution.