Let $F : \mathbb{R} \to \mathbb{R}$ be a D4364: Real function such that

(i)	$F$ is a D3249: Right-continuous function
(ii)	$F$ is an D5321: Standard-isotone basic real function

Let $\mathcal{I} = \{ (a, b] : a, b \in \mathbb{R}; a < b \}$ be the D3004: Set of right-closed real intervals in $\mathbb{R}$.
Let $\mathcal{C}(E) \subseteq \mathcal{P}(\mathcal{I})$ denote the D3041: Set of countable set covers of any $E \subseteq \mathbb{R}$ with respect to $\mathcal{I}$.
The Stieltjes outer measure on $\mathbb{R}$ with respect to $F$ is the D4361: Unsigned basic function \begin{equation} \mathcal{P}(\mathbb{R}) \to [0, \infty], \quad E \mapsto \inf_{C \in \mathcal{C}(E)} \sum_{(a, b] \in C} F(b) - F(a) \end{equation}