Count finishable joints
Map butt joints, tapered joints, inside corners, and other taped transitions from the board layout.
A layout with fewer seams can reduce tape and compound even when wall area is unchanged.
Keep tape and compound separate
Tape length follows joint geometry while compound consumption also depends on coat width, fasteners, bead, texture, and application technique.
Keep the assumption visible so it can be replaced when project or product data is available.
Match compound to the coat
Taping, all-purpose, topping, and setting compounds have different intended uses.
Use the product selected for embedding, fill, and finish coats rather than assuming one material performs every step.
Allow for application losses
Tooling, sanding, mixing, texture, and repairs can affect actual consumption.
Use documented job history or product guidance where available.
Verify the finishing system
Joint treatment must remain compatible with the gypsum panel and specified assembly.
Follow current manufacturer installation instructions for the chosen system.