How the flooring calculator works
Laminate, luxury vinyl planks and engineered wood are all sold by the pack, and every pack covers a stated area. The calculation is the same for each.
- Net area. Room length × width, or the area you enter, minus any fixed area you add such as a kitchen island.
- Cutting waste. A percentage for the laying pattern: 10 % straight, 15 % diagonal or herringbone. You can change it.
- Packs. Area with waste ÷ pack coverage, rounded up.
- Planks. If you entered plank size, the number of planks with waste, for checking against damaged boards.
- Underlay. Net area × 1.10 ÷ roll coverage, rounded up. The 10 % covers seams, trimming at the walls and roll-end offcuts.
Measuring the floor
Measure the longest and widest points of the room in metres. Include door thresholds and the floor of any built-in wardrobe you intend to floor. For an L-shaped room, add the two rectangles and enter the total area, or run the calculator twice and add the packs.
Laying pattern and waste
Straight planks parallel to the longest wall produce the least waste, because the offcut from the end of one row starts the next. Laying diagonally wastes a triangle at every wall. Herringbone wastes a triangle at every wall in both directions, and the pattern itself needs a careful start. The default waste allowances reflect this; increase them for rooms with many corners.
Pack sizes
Pack coverage differs between ranges even from the same brand, from about 1.7 m² to 2.7 m². Always read the figure from the pack you are buying. If you have the plank size and the number of planks per pack instead, use the plank option and the calculator multiplies them for you.
Worked example
A 5 × 4 m living room is 20 m². Laid straight with 10 % waste, the calculator needs 22 m² of flooring. With packs of 2.22 m² that is 9.91 packs, so 10 packs. The same room in herringbone with 15 % waste needs 23 m², which is 10.36 packs, so 11. If the pack instead lists eight planks of 1200 × 190 mm, each pack covers 1.824 m², so the straight lay needs 13 packs and 97 planks. Underlay in 10 m² rolls: the 20 m² net floor plus 10 % is 22 m², which is 2.2 rolls, so three rolls.