Abstract: The invention provides a mechanical lever buckle (400) that comprises a buckle base plate (402), a buckle prong (30) and a belt loop element (404) having a belt guiding means allowing to guide a belt in a belt guiding direction. The lever buckle (400) further comprises a lever element (406). The buckle base plate (402) comprises an elongated slit (412) with a direction corresponding to the belt guiding direction that allows to slide the buckle prong (30) in belt guiding direction of the slit (412). The lever element (406) comprises an elongated guiding opening (64) that allows to slide the buckle prong (30) in a first length direction of the guiding opening (64). The lever element (406) is attached to the buckle base plate (402) at a first of its extremities around a first rotation axis (61), such that during rotation of the lever element (406) the buckle prong (30) slides along the slit (412) and the elongated guiding opening (64).