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This flooring calculator works out how much laminate, luxury vinyl plank, engineered wood, hardwood or carpet you need for a room. Enter the room size and the coverage printed on the box, add a waste allowance, and it tells you exactly how many boxes to buy and what they will cost.
How to Use the Flooring Calculator
- Measure the length and width of the room at the widest points, wall to wall.
- Enter a waste allowance: 10% for straight installations, 15% for diagonal layouts and up to 20% for herringbone or chevron patterns.
- Enter the coverage per box, which is printed on the packaging (for example 20 sq ft or 2 m² per box).
- Optionally add the price per square foot or square meter to estimate the total cost.
- For L-shaped rooms or several rooms, calculate each rectangle separately and add the boxes together.
Flooring Formula
Area = Length × Width
Boxes = (Area × (1 + Waste %)) ÷ Coverage per box, rounded up
Flooring is sold by the full box, so the result is always rounded up. The calculator also shows the total coverage of the boxes you buy, which is the area you actually pay for.
Worked Example: 15 × 12 ft Living Room
- Area: 15 × 12 = 180 sq ft
- With 10% waste: 180 × 1.10 = 198 sq ft
- Boxes at 20 sq ft each: 198 ÷ 20 = 9.9, so buy 10 boxes (200 sq ft)
Metric example: a 4.5 × 3.6 m bedroom is 16.2 m². With 10% waste that is 17.8 m², so with packs of 2.0 m² you need 9 packs.
How Much Waste Should I Allow?
| Installation | Typical waste allowance |
|---|---|
| Straight lay in a simple rectangular room | 5–10% |
| Rooms with many corners, closets or doorways | 10–15% |
| Diagonal layout | 15% |
| Herringbone or chevron | 15–20% |
| Patterned carpet or tile-look vinyl that must match | 15–20% |
Measuring Tips
- Measure to the wall, not the baseboard. Expansion gaps are hidden under trim and are already covered by the waste allowance.
- Include closets, alcoves and the area under appliances that will sit on the new floor.
- Measure doorways to the middle of the door stop so the floor ends neatly under the door.
- Keep one or two spare boxes after the job for future repairs; the exact color may be discontinued later.
Other Things to Budget For
- Underlayment for laminate and some vinyl floors (usually sold in rolls covering 100 sq ft or 10 m²).
- Transition strips at doorways and where the new floor meets a different surface.
- Baseboard or quarter-round trim, adhesive or nails for glue-down or nail-down floors.
- Tiling a bathroom or kitchen instead? Use our tile calculator.
Frequently Asked Questions
How do I calculate how much flooring I need?
Multiply the room’s length by its width to get the area, add 10% for waste, then divide by the coverage on one box and round up to the next whole box.
How many boxes of flooring do I need for 200 square feet?
With 10% waste you need 220 sq ft. If each box covers 20 sq ft, that is 11 boxes. If each box covers 22 sq ft, it is 10 boxes.
Should I add 10% or 15% extra flooring?
Add 10% for a straight layout in a regular room. Use 15% for diagonal layouts or rooms with many corners and up to 20% for herringbone patterns.
Do I include closets when measuring flooring?
Yes. If the new floor continues into closets, alcoves or under appliances, include those areas in your measurements.
Does this calculator work in square meters?
Yes. Switch to metric, enter the room size in meters and the pack coverage in square meters.
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