The short answer
Measure the room wall to wall at its widest points, split any odd shapes into rectangles and add the areas. Then add a waste allowance, commonly 5–10% for a straight lay, and divide by the coverage on the pack, rounding up. A 4 × 3 m room with 10% waste and packs of 2.2 m² needs 6 packs.
Try the Flooring CalculatorMeasure wall to wall
Measure the length and width of the room along the floor from wall to wall, at the widest points. Do it at skirting level, because walls are not always square, and measure each side twice. The area is length times width, in square metres.
Measure in one unit, such as metres or centimetres, and write the figures down as you go. If you work in feet and inches, convert to metres before you multiply.
Split odd shapes into rectangles
For an L-shaped room, an alcove or a bay, draw a quick sketch and divide the floor into rectangles. Measure each rectangle, work out its area, and add them together.
For example, a 4 × 3 m main room plus a 2 × 1.5 m alcove is 12 + 3 = 15 m². With a 10% allowance that is 16.5 m², which needs 7.5 packs of 2.2 m², so 8 packs.
Doorways, units and fixed items
Include the floor in the doorway, measuring to the middle of the door opening where the floor normally changes. Also include cupboards and recesses you will floor, such as the space under a radiator.
Leave out fitted kitchen units and appliances that will not be moved, because flooring is not usually laid beneath them. Follow the manufacturer's instructions, since some products need a continuous floor.
Add waste, then buy whole packs
Add an allowance for cuts and offcuts: commonly 5–10% for a straight lay in a simple room, and 10–15% for diagonal or herringbone layouts or rooms with many corners. Tiles are counted separately by the number in each row and column, so use the tile calculator for them.
Divide the area with waste by the coverage printed on the pack and round up to a whole pack. Buy all packs from the same batch, and keep the leftovers for repairs. The flooring calculator does this step for you.
Before you order
Check the sub-floor is flat, dry and clean, and follow the manufacturer's instructions on the maximum run, the expansion gap around the edge and acclimatising the packs in the room before fitting.
Measure for skirting boards or trims at the same time. The length of wall is easy to find while you are measuring the floor, and the skirting board calculator can turn it into a number of boards.
This guide is general information to help you plan, not professional advice. Check product instructions and your supplier's guidance before you buy, and ask a qualified professional about structural or safety-related work. See our terms of use.