Jobmath

Drywall calculator

Enter the room and the sheet size. Jobmath removes doors and windows and adds extra for cuts.

How it's calculated

Each step, in the order Jobmath runs it.

StepFormula
Wall area2 × (length + width) × wall height
Ceiling areaLength × width
Area to coverWalls + ceiling − doors and windows
SheetsArea × (1 + waste %) ÷ sheet area, rounded up

Sheet sizes

Longer sheets mean fewer seams to tape and finish.

SheetAreaCommon use
4' × 8'32 sq ftWalls up to 8 ft, easiest to carry
4' × 10'40 sq ft9 and 10 ft walls
4' × 12'48 sq ftFewer seams on long walls and ceilings
4.5' × 12'54 sq ft9 ft walls hung horizontally, two rows