How to Calculate Flooring Square Footage
The measuring method that prevents short orders: break the space into rectangles, measure twice, and add a waste allowance.
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- Time to measure
- 10–20 minutes
- Difficulty
- Easy
- You need
- Tape measure, paper, calculator
To calculate flooring square footage, measure the length and width of each rectangular area in feet and multiply them together. Add the areas of all rectangles, then add a waste allowance before you order.
Step by step
- Sketch the room and mark any alcoves, closets, or offsets.
- Split the space into rectangles. Measure the length and width of each one in feet.
- Multiply length by width for each rectangle to get its area in square feet.
- Add the areas together for the total square footage.
- Add a waste allowance of at least 10% for cuts and future repairs.
Worked example: an L-shaped room
A main area measuring 12 ft by 10 ft, plus an alcove measuring 6 ft by 4 ft:
main area = 12 × 10 = 120 sq ft
alcove = 6 × 4 = 24 sq ft
total = 120 + 24 = 144 sq ft
with 10% waste = 144 × 1.10 = 158.4 sq ftUse the square footage calculator to add up rectangles, or the flooring calculator to include a waste allowance and convert to boxes.
Measuring tips
- Measure at the widest point of each area, not in the middle where furniture sits.
- Round each measurement up to the nearest inch before converting to feet.
- Measure twice. A small error on a large room can change how many boxes you order.
- Note doorways and transitions where flooring stops or changes direction.
Do not order the bare area
Cuts around doorways, corners, and vents create waste. Ordering the exact measured area is the most common reason a flooring job runs short.
Sources and assumptions
The method here is standard area measurement. Waste allowances are rules of thumb that vary by layout and installer.
Frequently asked questions
- How do I measure an L-shaped room?
- Split the room into two or more rectangles at the corners, measure each rectangle separately, and add the areas together. A 12 x 10 ft main area plus a 6 x 4 ft alcove is 120 + 24 = 144 sq ft.
- Do I include closets in floor square footage?
- If you are flooring inside them, yes. Measure each closet as its own rectangle and add it to the total. If they are staying carpeted, leave them out.
- How much waste should I add for flooring?
- Ten percent is a common starting allowance. Use 15% or more for diagonal or patterned layouts, rooms with many corners, or if you want extra material for future repairs.