Start with the correct unit of measurement
Plasters are compared at the same thickness. Norm in kg/m²/mm describes quantity per square meter and one millimeter layer. A g/m rate for a joint uses the linear length, not the area of the entire wall.
Drywall and mineral wool are planned by area and layers. Profiles require placement and cutting, and screws require a specific fastening scheme. Do not apply a single standard to all systems.
An example of a preliminary estimate
For 100 m² of plaster MP 75 and an average thickness of 10 mm, the published 10 kg/m² gives a theoretical 1000 kg of dry material. This is a calculation according to the norm, without added losses and without correction for real irregularities.
For Super Finish putty at 100 m² and 1 mm layer, the nominal 1.56 kg/m²/mm gives 156 kg. This example is not interchangeable with the consumption of machining only the joints.
What is checked on site
Actual surfaces are measured, layers are specified, and proofing is done if necessary. Variations in substrate, tool, and method of operation change the practical amount.
Compare the exact product, market and datasheet. The packaging shown is illustrative; the bill of quantities is based on the actual package selected.