How to Measure a Room for Flooring
Measure the room's square footage, then add a waste factor on top — 10% for straight-lay flooring, 15% or more for diagonal layouts or rooms with lots of angles.
Measure the room’s square footage — length times width, in feet — then add a waste factor on top to cover cuts, trimming, and mistakes. For a simple rectangular room with a straight-lay pattern, add 10%. For rooms with more angles, doorways, or a diagonal layout, add 15% or more.
Step 1: Get the room’s square footage
Measure wall-to-wall for length and width, then multiply. For an irregular room, split it into rectangles first — see how to measure a room’s square footage for the full breakdown of that process.
Include any closets, alcoves, or nooks the flooring will actually cover.
Step 2: Add a waste factor
Flooring materials are sold in fixed unit sizes (planks, tiles, or rolls), and installation always produces some unusable offcuts. Buying exactly the room’s square footage means running short partway through the job.
| Layout | Recommended waste factor |
|---|---|
| Simple rectangular room, straight lay | 10% |
| Room with multiple doorways, closets, or angled walls | 15% |
| Diagonal layout, herringbone, or chevron pattern | 15–20% |
Example: A 200 sq ft room, straight-lay, 10% waste → order 220 sq ft of material.
Step 3: Account for the doorway and transitions
If the flooring continues into a hallway or adjoining room through a doorway, decide where the transition strip will sit and measure that connecting area separately — it’s easy to forget the few square feet inside a doorway threshold.
Step 4: Check the material’s coverage per box
Flooring is typically sold by the box, with a stated square-foot coverage per box (commonly 20–24 sq ft for laminate or vinyl plank). Divide your total (room square footage plus waste) by the per-box coverage, and round up — you always want a whole number of boxes, never a fraction.
Example: 220 sq ft needed ÷ 22 sq ft per box = 10 boxes exactly. If it came out to 9.3 boxes, you’d still buy 10.
A few things that catch people off guard
- Plank direction affects waste, not the base square footage — running planks the long way across a room typically wastes less material than a diagonal layout.
- Dye lots vary between boxes manufactured at different times. Buying all your boxes at once, from the same lot, avoids visible color mismatches.
- Keep the leftover material. A box or two of extra flooring is useful for future repairs, since matching a discontinued style later can be difficult.