Flooring Calculator
Work out how many boxes of flooring a room or set of rooms needs.
Last reviewed September 19, 2026
Result
Enter rooms and sections to see the result.
https://calcgallery.com/flooring-tile/flooring-calculator/
Results are estimates for planning only. Actual needs vary with site conditions, products and workmanship. Always confirm quantities with your supplier and follow local building codes and manufacturer instructions. Read the full disclaimer
How to use it
- Enter each room as a rectangle. Add a row per room, or per rectangle if a room is an L-shape.
- Enter the coverage printed on the box, not the nominal size.
- Pick the layout. Diagonal and herringbone waste considerably more.
- Read the box count.
How it is calculated
Every rectangle you enter is added together first, then the boxes are worked out once from the total:
Area = sum of every rectangle
Boxes = ceil(area × (1 + waste) ÷ coverage per box)Summing first matters. Rounding each room up to whole boxes and adding those buys more than you need, sometimes by two or three boxes across a house, because each room wastes part of its last box.
The allowance covers cuts, and how much you waste depends mostly on the layout rather than the room. A straight lay along the long wall wastes least. A diagonal turns every perimeter cut into an angle, and the offcut from one wall rarely starts the next row.
Practical tips
Let it acclimatise. Most timber and laminate needs a few days in the room before it goes down, so it reaches the moisture content it will live at. Fitting it straight off the van is how you get gaps in winter and buckling in summer.
Plan the first row and the last. Measure the room and work out how wide the last row will be. If it lands at 20 mm, trim the first row instead so both ends are a sensible width. Doing that after you have started is not possible.
Keep the offcuts until the end. The piece cut off the end of one row usually starts the next. Sweeping them up as you go means cutting two boards where one would have done, which is where the waste allowance actually goes.
Check every box as you open it. Shade varies between boxes, and mixing boards from three open boxes as you lay spreads it out. Working through one box at a time can leave a visibly different patch.
Expansion gap around everything. Floating floors move. A gap at every wall, pipe and threshold, covered by the skirting or a trim, is what stops the floor lifting in the middle of the room in August.
With your numbers
- Total floor = 200 ft²
- With 10% for cuts = 220 ft²
- Boxes = that ÷ 22.5 ft² per box, rounded up to 10
Quick reference
Boards get cut at every wall and doorway, and the offcuts rarely start the next row, so this includes 10% extra.
| Job | Boxes to buy |
|---|---|
| 10 × 12 ft room | 6 |
| 12 × 15 ft room | 9 |
| 200 ft² of floor | 10 |
| Two rooms, 10 × 12 and 8 × 10 ft | 10 |
| L-shape, 12 × 15 plus 6 × 8 ft | 12 |
| 3 × 4 m room | 7 |
| 4 × 5 m room | 11 |
| Two rooms, 3 × 4 and 2.5 × 3 m | 11 |
Common questions
- How many boxes of flooring for 200 square feet?
- 10 boxes at 22.5 ft² per box with a 10% allowance. Without the allowance it is 9, and you would run out somewhere in the last row.
- Why does the box say a different coverage than I measured?
- Boxes state usable coverage, which is the actual board face, not the nominal size. Some manufacturers state both. Always use the coverage figure, which is what this asks for.
- How much extra should I buy?
- 10% for a straight lay in a simple room. 15% or more for a diagonal, and 20% for herringbone. Add more again for a room with lots of doorways, alcoves or angles, because each one is another cut.
- Should I buy a spare box?
- Yes, if you can. Flooring is produced in batches that vary in shade, and lines are discontinued constantly. A spare box in the loft is the difference between replacing three damaged boards and replacing a floor.
- Can I add up several rooms at once?
- Yes, that is what the rows are for. Add each room or section and they are summed before the box count is worked out, which buys fewer boxes than rounding up room by room.
- Does this work for carpet or sheet vinyl?
- Not well. Those come off a roll at a fixed width, so the waste depends on how the room fits the roll rather than on area. This is for anything sold by the box.