Plywood Sheet Calculator

About this calculator

This calculator divides the area you need to cover by the area of a single plywood or OSB sheet (commonly 4×8 ft, i.e. 32 sq ft) to get a raw sheet count, then adds a standard 10% waste allowance to cover cutting losses, mistakes and irregular room shapes, rounding up to a whole number of sheets.

Builders, contractors and DIY renovators use this before a materials run to a lumber yard, since underbuying means a second trip (and possibly a different batch with slightly different thickness or color) while overbuying wastes money on sheets that go unused. The 10% margin is a widely used contractor rule of thumb for flat sheet-goods projects like subfloors, roof decking and wall sheathing.