Worldwide
Flooring calculator
Flooring is sold by the pack, not by the square metre, so the real question in the shop is not how big the room is but how many packs to lift into the trolley.
Works for laminate, engineered wood, vinyl planks or tiles sold by the pack.
This calculator answers that. It takes the room length and width, works out the floor area, adds a waste margin for the offcuts every job produces, and divides by the area one pack covers, rounding up because a part pack is not for sale. You get the packs to buy, the bare floor area, the area once waste is added, and the total coverage you carry home. The floor area is the easy part: length times width for a rectangular room. The pack coverage is printed on the box, usually between about 1.5 and 2.5 square metres for laminate and engineered boards, and the waste allowance is where most people under-buy. Cutting planks to length at the walls always leaves end pieces too short to reuse, and the last row is rarely a full plank wide, so a straight lay in a plain rectangle loses around 10 percent to waste. A diagonal or herringbone layout, a busy pattern that has to line up, or a room full of alcoves, bay windows and pipe boxings can lose 15 percent or more. The tool defaults to 10 percent and lets you raise it. Rounding up matters because flooring comes in fixed pack sizes and dye lots shift between production batches, so going back for one more pack weeks later can leave a visible colour difference. People use this for laminate, engineered wood, vinyl planks, LVT and floor tiles, all of which are boxed by coverage. For an L-shaped or stepped room, split the floor into rectangles, work out each area, and add them before applying the waste. Treat the pack count as the number to buy, and keep one spare pack sealed for the repair you will be glad of if a board is ever damaged.
How it works
- Measure the room length and width in metres and enter them.
- Set a waste allowance: about 10 percent for a straight lay, 15 percent or more for diagonal or patterned floors.
- Enter the area one pack covers, printed on the box in square metres.
- The tool finds the floor area, adds the waste, and divides by the pack coverage.
- It rounds up to whole packs and shows the total area you will have bought.
packs = ceil( length x width x (1 + waste) / pack coverage )
The floor area is length times width. Multiplying by one plus the waste fraction adds the offcuts and trimming losses that every fitted floor produces. Dividing by the area one pack covers gives the packs needed in exact terms, and rounding that up to the next whole number reflects that flooring is sold only in full packs. The total coverage bought is then the whole pack count times the pack area, always a little above the area-with-waste because of the rounding.
- length, width
- room dimensions in metres
- waste
- fraction added for offcuts, 0.10 for a straight lay
- pack coverage
- square metres one pack covers, from the box
- ceil
- round up, since part packs are not sold
Waste allowance by layout
| Straight lay, simple rectangle | about 10 percent | the common starting point |
| Diagonal lay | about 15 percent | more angled cuts at the walls |
| Herringbone or chevron | 15 to 20 percent | short pieces, careful matching |
| Busy room, alcoves and bays | 15 percent or more | offcuts rarely reuse |
Worked example
A 5 by 4 metre room, a 10 percent waste allowance, and laminate packs covering 2.5 m² each: the floor is 20 m², which becomes 22 m² once the 10 percent waste is added. At 2.5 m² a pack that is 8.8 packs, rounded up to 9, so you carry home 22.5 m² of flooring. The 0.5 m² over the waste figure is the rounding to whole packs, and it doubles as a sealed spare. Switch to a herringbone lay at 15 percent waste and the same room needs 23 m², which is 10 packs at this coverage.
Key facts
- Flooring is bought by the pack, so the answer is always whole packs, rounded up.
- A straight lay in a plain room loses roughly 10 percent to offcuts.
- Diagonal and herringbone patterns waste noticeably more material.
- Dye lots vary between batches, so a later top-up pack may not match.
Tips
- Measure at the widest points and into doorways, where flooring usually runs through.
- Buy all the packs in one order so they share a dye lot and match exactly.
- Keep one sealed spare pack with the original batch number noted for future repairs.
- Order underlay to the bare area and edge trims to the room perimeter at the same time.
Frequently asked questions
Why does the tool round up to whole packs?+
Flooring is sold only in full packs, so any fraction means you are a few boards short and must buy another pack anyway. The calculator rounds up for you, which is why a 22 m² job at 2.5 m² a pack comes out as 9 packs (22.5 m²) rather than 8.8. The small surplus is normal and useful as a spare.
How much waste should I allow?+
About 10 percent suits a straight lay in a simple rectangular room. Allow 15 percent for a diagonal layout or a pattern that must line up, and more again for rooms with bay windows, alcoves, many doorways or pipe boxings, where short offcuts pile up. When in doubt, round the waste up rather than down.
Where do I find the pack coverage?+
It is printed on the end of the box, given as square metres per pack. Laminate and engineered boards are often 1.5 to 2.5 m² a pack, while tiles and vinyl vary widely. Use the exact figure for the product you are buying, since pack sizes differ even between ranges from the same brand.
What about an L-shaped or odd room?+
Split the floor into rectangles, work out the area of each (length times width), add them together, and use that total. Then apply the waste allowance to the combined area. Subtracting a fixed feature like a kitchen island only helps if it is large; for small obstructions it is safer to leave the area in.
Why keep a spare pack?+
Flooring is made in batches called dye lots, and the colour and grain can shift slightly between them. If a board is ever scratched or water-damaged, a sealed spare from the original batch matches perfectly, whereas a fresh pack bought later may not. One spare pack is cheap insurance against a patch repair that stands out.
Does this include underlay or trims?+
No. Underlay is sold by the roll to the bare floor area, and beading, threshold strips and scotia are sold by length to the room perimeter. Work those out separately: the perimeter is the sum of the wall lengths, the same figure a wallpaper estimate starts from.
Things to watch
- Under-ordering risks a colour mismatch if you top up from a different batch later.
- The default waste suits a simple room; complex layouts and patterns need a higher figure.
- This counts the flooring only, not underlay, adhesive, beading or threshold strips.
Last updated: 2026
This is an estimate for general guidance, not financial, tax, legal or medical advice. Figures can change and individual circumstances vary. Always confirm with an official source before making decisions.
Built and maintained by Vikas Dulgunde. Editorial standards.