Quick answer
For a rectangle multiply length × width. For an L-shaped room divide it into rectangles, calculate each area and add them. Apply waste only after the measured total is complete.
Step by step
- Sketch the footprint Mark closets, alcoves and permanent untiled areas.
- Split irregular shapes Use rectangles that do not overlap.
- Add measured areas Keep all dimensions in the same unit.
- Apply waste and boxes Use layout complexity and exact carton coverage.
Formula or rule of thumb
total area = area 1 + area 2 + ...; boxes = ceil(area × waste ÷ box coverage)
Example
A 12 × 10 room plus a 3 × 4 alcove is 120 + 12 = 132 ft² before waste.
Common mistakes
Double-counting an L-shaped corner, subtracting movable furniture, and rounding each section separately.
Planning note: product yields, installation methods, site conditions and local requirements can change the final quantity. Use the exact manufacturer or supplier information before purchasing.
FAQ
Do I include closets?
Include them if they receive the same flooring.
Do I subtract cabinets?
Subtract only fixed areas that definitely will not be covered.
When is waste added?
After total measured area, before package rounding.