A dosing device includes a rod element and a shell. The rod element has a stem with a longitudinal axis and a first thread arrangement. The shell has a second thread arrangement. The first thread arrangement of the rod element or the second thread arrangement of the shell includes a thread. The first thread arrangement of the rod element and the second thread arrangement of the shell engage. The rod element is movable along the longitudinal axis of its stem by rotating the shell and the rod element relative to each other causing the first thread arrangement of the rod element and the second thread arrangement of the shell to travel along each other. A dosage chamber is formed by moving the rod element along the longitudinal axis of its stem. The volume of the dosage chamber is varied by moving the rod element along the longitudinal axis of its stem. An inclination angle (α, β) of the thread varies along the thread. The dosing device according to the invention can allow for a precise and convenient dosing of a liquid out of a container. In particular, it can allow for efficiently dosing a comparably small volume out of a comparably large container.