How much flooring do you need? Calculating area and wastage

Order too little and the fitting stops while you wait for another batch. Order too much and you have paid for flooring that will sit in a garage. This short guide walks through calculating the exact quantity of parquet — or vinyl, or tiles — you need, first time. Want the number straight away? Use our interactive flooring calculator: enter the dimensions and you have your quantity in seconds.

How to calculate floor area — the basic formula

Floor area is simply the size of the surface in square metres. For a rectangular room the principle behind how to calculate floor area is as simple as it sounds: multiply the length by the width.

Floor area (m²) = Length × Width

For example: 6.5 m × 4.2 m = 27.3 m². That is the room area — the base figure every flooring calculation starts from.

Measuring for flooring: what to subtract

Measuring for flooring is slightly different from measuring a room, because you need to deduct the areas the flooring will never reach. In practice:

• Kitchen islands and fitted units — deduct the footprint if the floor stops at the plinth.
• Fireplace hearths, columns, built-in wardrobes — deduct these as well.
• Doorways — leave them in if the floor runs through from room to room; deduct them if you are fitting a threshold.

It is quicker and more accurate to let the area calculator do it: enter length, width and any deductions, choose the laying pattern, and you have the quantity in seconds. It adds the right wastage allowance for the pattern you pick and works out the skirting at the same time.

Awkward room shapes

For an L-shaped room, split the plan into rectangles and add the areas together. For angled corners and curves:

• Triangle: (base × height) / 2
• Circle: π × r² (where r is the radius)

If you are not confident with the measurements, photograph the floor plan and send it to us — we will do the calculation free of charge.

How much wastage should you add?

This is the part that matters most, and the part people most often get wrong. The allowance depends on how the floor is laid:

Laying pattern	Wastage
Straight — parallel to the wall	+ 5–7 %
Straight — along the length of the room	+ 7–10 %
Diagonal (45°)	+ 10–12 %
Herringbone	+ 10–15 %
Rooms with many corners or narrow hallways	+ up to 15 %

Worked through: 27.3 m² × 1.08 (8 %) = 29.5 m² for a straight lay.

Round up to whole packs

Parquet is sold in packs holding a fixed number of square metres — you cannot buy half a pack. The Dimensions and m² per pack rows on every product page give the exact figures. The usual ones:

• Standard 1900 × 190 × 14 mm — 2.888 m² per pack
• Wide plank 1900 × 240 × 14 mm — 2.736 m² per pack
• XL 2200 × 240 × 15 mm — 3.168 m² per pack
• Herringbone blocks 600 × 120 × 14 mm — 0.576 m² per pack
• SPC vinyl flooring — usually 2.525 m² per pack (for the difference between SPC and LVT, see our guides)

Always round up: 29.5 m² ÷ 2.888 = 10.21, so you order 11 packs (= 31.77 m²). Our product pages do this for you — enter the area and the pack count appears.

Should you keep a spare pack?

We strongly recommend keeping one unopened pack once the floor is down. Three reasons:

• Natural oak varies between production batches — in three to five years the identical shade may no longer exist.
• If a few boards are damaged by water or an impact, they can be replaced individually rather than relifting the whole room.
• An unopened pack keeps its factory finish and moisture content, so the repair is invisible.

Do not forget the ancillaries

Alongside the flooring itself you will need:

• Underlay — the same area as the flooring (2–3 mm acoustic underlay, or a Triton-type product where there is underfloor heating).
• Skirting — perimeter × 1.1 to allow for mitred corners. A 21 m perimeter means 24 linear metres.
• Adhesive, for a glue-down installation — 1.0–1.2 kg/m² of SMP adhesive. A 27 m² project needs roughly 32 kg, so 2 × 21 kg tubs. Our full installation guide and subfloor preparation guide cover the method.
• Transitions between rooms — thresholds and transition profiles, counted by the number of doorways.

Common mistakes

“It looked like it would be enough — I ordered the size of the room.” The classic error, and one of the most common reasons a fitting date slips.

• Alcoves and narrow runs left out — the strip by a doorway or out to a terrace door is easy to miss on a plan.
• Too little wastage for herringbone — the perimeter is full of angled cuts, so offcuts add up faster than in a straight lay.
• No spare pack — a few years on, a small localised repair turns into an expensive job.

A quick final check

Before you pay, confirm that you have:

1. Added the right wastage percentage for your laying pattern.
2. Rounded up to whole packs.
3. Added one spare pack for the future.
4. Included underlay, adhesive and skirting.

Still unsure? Book a free consultation or send us your floor plan through the contact page — we will work the quantities out for you at no cost.