Is there any way or plugin which allows enter material density in [kg/m³] instead of direct enter real mass [kg] how it is now in Blender. Blender knows the exact size of the object, so it is possible to calculate volume [m³] and then evaluate weight [kg] based on material density. I personally don't understand why there is just weight [kg] by default. With material density, there could be also possible to preselect common material like wood, steel, iron, plastic, glass, etc. It will allow us to make more realistic physics animation in a much shorter time. Do it now with many objects on the scenes is horrible.
I found the solution, it is directly in blender itself.
Horizontal menu bar > Object > Rigid Body > Calculate Mass
As you can see here on the screenshot:
Bad thing is that you need to do it every time you change the side of the object. It is not updated automatically.