Construction
Subfloor Area Calculator
Calculate subfloor area with a waste allowance and an approximate sheet count.
Formula
Floor area = length multiplied by width. Area with waste = area multiplied by (1 + waste as a decimal). Sheet count = waste area divided by 2.88 square metres per standard sheet, rounded up.
How it works
Measure the floor's length and width, then add a waste percentage for cuts around edges and obstacles. Dividing by a standard sheet size gives a sheet count for ordering. Rooms with many corners or angles need a higher waste allowance.
FAQs
Why 2.88 square metres per sheet?
That is the area of a common 2400 by 1200 millimetre sheet. If your sheets differ, adjust the count accordingly.
How much waste is normal?
Ten percent suits simple rectangles; complex rooms may need fifteen percent or more.
Does this include adhesive and fixings?
No, those are ordered separately based on the sheet count and manufacturer guidance.
Rough estimate only — consult a licensed professional for structural work before building.