How many packs of flooring do I need, and how much waste should I allow?
Turning a room into an order in the units the shop sells in, with an honest waste allowance for the pattern, the room shape and the offcuts you will not be able to use.
- Difficulty
- beginner
- Time
- 25 min
- Read
- 3 min
Short answer
Measure the floor area including under radiators and into every recess and doorway, then add a waste allowance: around 5% for a simple rectangular room, 10% for an average room with a bay or an awkward shape, and 15% or more for a diagonal or herringbone layout. Then round up to whole packs, and buy the spare pack.
Flooring is sold by the pack, each covering a stated area, and every pack you open past the first one you needed is a pack you cannot return. Getting the quantity right is a five-minute calculation, and getting it wrong means either a second trip to find the batch discontinued or two spare packs in the loft.
What you'll need
- a tape measure
- a rough plan of the room
- the pack coverage figure from the product
Step by step
- Draw the room and break it into rectangles.Every room is a set of rectangles plus a few odd corners. Measure each one at its widest, and measure into doorways, bay windows, alcoves and under radiators — the floor goes there too.
- Measure at floor level, not at waist height.Skirtings, plaster and old walls mean a room is a different size at the bottom than in the middle. Take every measurement at the floor.
- Add the areas up.Length times width for each rectangle, then total. Do not subtract anything for a kitchen island or a fitted unit unless you have decided the floor genuinely does not go under it.
- Choose the waste allowance for your layout.Straight plank layout in a simple rectangular room: around 5%. A normal room with a bay, a chimney breast or an angled wall: around 10%. Diagonal, herringbone or chevron: 15% and upwards, because every board is cut twice.
- Add more for a strongly patterned or shaded product.Products with strong colour variation between planks need more selection and rejection during laying. So does a floor with a repeating printed pattern that has to be avoided, which needs planks set aside.
- Convert to packs, always rounding up.Divide the total including waste by the coverage per pack, and round up to the next whole pack. Never round down and hope.
- Buy one more pack than the sum.For repairs. Ranges are discontinued and batches shade differently, and a spare pack in the loft is the only way to repair a floor in five years. This is not upselling — it is the cheapest insurance in the job.
- Check that all packs are the same batch.The batch number is printed on the pack. Different batches of the same product can differ visibly in shade. Check before you leave the shop and mix packs as you lay so any variation is distributed rather than concentrated.
- Check the returns policy on unopened packs.Many retailers accept unopened packs back within a period. If so, buying generously costs nothing but a trip. If not, the calculation has to be tighter.
Tips
- Offcuts from the end of one row start the next row, which is where the waste allowance actually comes from — a room where the offcut is always too short to reuse generates far more waste than one where it works out.
- Measure the room diagonally as well as squarely. A room that is significantly out of square needs more waste, because the cuts along one wall are tapered.
- If the floor runs through into a hall or another room, measure and buy for the whole run at once. A continuous floor cannot be topped up later from a different batch without it showing.