Here, we can see a weight of material chart, which contains different materials, and different thicknesses. This is an example of a chart that you could use at a shipyard for doing quick weight calculations based on the area of an object that has homogeneous thickness. Sheets of material could fall under this category as well as hollow pipes to name a few. Please note that if the thickness of the material is not homogeneous, then you can not use this type of charts.
This is a sample weight chart of multiple metal alloys by thickness that could be used to calculate the weight of a sheet of material.