Count panels first
Separate walls, ceilings, shafts, wet areas, and fire- or moisture-rated assemblies where board types differ.
Use a sheet layout rather than relying only on gross square footage.
Measure joints and corners
Estimate tape from board joints and inside corners, then count outside corners or trims separately.
Finish details can change accessory quantities materially.
Count fasteners from the assembly
Fastener quantity depends on framing spacing, panel orientation, layers, and the required fastening schedule.
Use the applicable assembly and manufacturer instructions rather than a generic screws-per-sheet value.
Use compound yield data
Joint-compound demand varies with finish level, joint type, bead, texture, and product formulation.
Use current manufacturer coverage or estimating data and keep a documented allowance separate.