A measuring device adapted to measure a distance between an edge of a platform and a sill of a rail vehicle, the measuring device comprising a measuring tool adapted to measure a first distance (E 1) between the edge of the platform and the sill of the rail vehicle, the first distance (E 1) being measured in a transverse direction of the rail vehicle, the measuring tool comprising: - a support adapted to be installed on the edge of the dock, the support having at least one locating surface for abutting the dock in the transverse direction and in an elevation direction substantially normal to the transverse direction; - a movable part mounted on the support and translatable relative to the support in a first direction between a plurality of positions, including a measuring position in which the support is intended to abut the edge of the dock and the movable part is intended to abut the sill of the rail vehicle; and - an indicator system of the first deviation (E 1) adapted to provide first information representative of the first deviation (E 1) when the movable part is in the measuring position, the measuring device further comprising an aiming member adapted to project a beam onto the moving part, the aiming member preferably being a laser level, the measuring tool being further adapted to cooperate with the sighting member to provide second information representative of a second deviation (E 2) between the edge of the platform and the sill in the direction of elevation, the movable part being adapted to form a target capable of cooperating with the sighting member to provide the second piece of information representative of the second deviation (E 2). - a support adapted to be installed on the edge of the dock, the support having at least one locating surface for abutting the dock in the transverse direction and in an elevation direction substantially normal to the transverse direction; - a movable part mounted on the support and translatable relative to the support in a first direction between a plurality of positions, including a measuring position in which the support is intended to abut the edge of the dock and the movable part is intended to abut the sill of the rail vehicle; and - an indicator system of the first deviation (E 1) adapted to provide first information representative of the first deviation (E 1) when the movable part is in the measuring position, the measuring device further comprising an aiming member adapted to project a beam onto the moving part, the aiming member preferably being a laser level, the measuring tool being further adapted to cooperate with the sighting member to provide second information representative of a second deviation (E 2) between the edge of the platform and the sill in the direction of elevation, the movable part being adapted to form a target capable of cooperating with the sighting member to provide the second piece of information representative of the second deviation (E 2). the measuring device further comprising an aiming member adapted to project a beam onto the moving part, the aiming member preferably being a laser level, the measuring tool being further adapted to cooperate with the sighting member to provide second information representative of a second deviation (E 2) between the edge of the platform and the sill in the direction of elevation, the movable part being adapted to form a target capable of cooperating with the sighting member to provide the second piece of information representative of the second deviation (E 2).