Flooring Calculator - Area, Packs, Underlay and Skirting
Get exact floor area, packs to buy, underlay, skirting, beading and expansion gaps for laminate, hardwood, LVT, engineered wood, vinyl, carpet, tile or vinyl plank. Includes wastage, plank orientation and full cost.
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Total Floor Area and Packs
Full Material Breakdown
| Item | Quantity | Notes |
|---|
Accessories and Trim
| Item | Quantity |
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Pick your flooring type, enter the room dimensions, and the calculator returns packs, underlay, skirting and every accessory you need.
Wastage by Flooring Type and Layout
Wastage varies by material and how you lay it. These are industry-standard allowances for real projects.
| Flooring type | Straight lay | Diagonal | Herringbone | Notes |
|---|---|---|---|---|
| Laminate | 5 - 8% | 10 - 12% | 12 - 15% | Clicks together easily |
| Engineered wood | 5 - 8% | 10 - 12% | 12 - 15% | Cut like solid wood |
| Solid hardwood | 8 - 10% | 12 - 15% | 15 - 20% | Grain matching matters |
| LVT / LVP | 5 - 8% | 10 - 12% | 12 - 15% | Flexible, easy to cut |
| Sheet vinyl | 10 - 15% | N/A | N/A | Roll width patterns |
| Carpet | 5 - 10% | N/A | N/A | Roll direction matters |
| Ceramic / porcelain tile | 8 - 10% | 12 - 15% | 15 - 20% | Cuts break occasionally |
Underlay Types and Their Uses
Underlay affects comfort, sound insulation and how long the floor lasts. Match the type to the material above it.
| Underlay | Thickness | Best for | Not for |
|---|---|---|---|
| Foam | 2 mm | Laminate, budget installs | Solid wood, LVT |
| Combination (foil-foam) | 3 mm | Laminate over concrete | LVT, glue-down |
| Acoustic fiberboard | 5 mm | Laminate, engineered wood upstairs | Underfloor heating |
| Rubber | 3 - 6 mm | Engineered wood, apartments | Laminate click (too soft) |
| PU / PE foam with barrier | 2 - 3 mm | Laminate over concrete slab | Solid wood |
| Gripper / tackless strip | N/A | Carpet | Hard floors |
| Self-levelling compound | 3 - 10 mm | Any floor over uneven subfloor | N/A |
Skirting Board vs Beading
Both hide the expansion gap around the perimeter. Which one you choose changes the trim material and how you finish the floor.
| Method | When to use | Materials needed |
|---|---|---|
| Remove and refit skirting | New build, full renovation | Skirting board, adhesive, sealant, paint |
| Leave skirting, add beading | Quick install, keep existing | Scotia beading, adhesive, sealant |
| Door undercut | Floor meets doorway | Door saw, threshold bar |
| Threshold bar | Transition between rooms or materials | T-bar or cover strip, adhesive |
How the Flooring Calculator Works
Every result uses standard flooring estimation methods. Here is the exact process.
- Floor area = room length × room width.
- Wastage depends on the flooring material and the laying pattern - straight lay uses 5 - 10%, diagonal uses 10 - 12%, herringbone uses 15 - 20%.
- Total area with waste = floor area × (1 + wastage %).
- Packs needed = total area ÷ coverage per pack, rounded up.
- Underlay area = floor area plus 5% overlap.
- Skirting length = perimeter, minus doorways (each door is 0.9 m of skirting not needed).
- Beading length = same perimeter if you're not removing skirting.
- Threshold bars = number of doorways and material transitions.
Flooring Formulas and Worked Example
These are the exact formulas used by the calculator. Bookmark this section if you want to verify the numbers yourself.
- Floor area = length × width
- Total area = floor area × (1 + wastage)
- Packs = ceil(total area ÷ coverage per pack)
- Underlay = floor area × 1.05
- Perimeter = 2 × (length + width)
- Skirting length = perimeter - (doors × 0.9 m)
- Threshold bars = doors + transitions
Worked example: A 5 m × 4 m room with laminate, laid straight. Floor area = 20 m². Wastage = 8% = 1.6 m². Total area = 21.6 m². Coverage per pack = 2.2 m². Packs = 21.6 ÷ 2.2 = 9.8 → 10 packs. Underlay = 20 × 1.05 = 21 m². Perimeter = 18 m. With 1 door (0.9 m), skirting = 17.1 m → buy 18 m to allow for cuts. Threshold bars = 1.
Frequently Asked Questions About Flooring Calculation
How do I calculate how much flooring I need?
Measure the room length and width, multiply them for the floor area, then add 5 - 10% for wastage. For a 5 × 4 m room, that is 20 m² plus 8% waste = 21.6 m². Divide by the coverage of one pack (usually 2.2 m² for laminate), round up, and you have your pack count.
How much waste should I allow for flooring?
For straight lay, add 5 - 8%. For diagonal lay, add 10 - 12%. For herringbone, add 15 - 20%. Solid hardwood needs more waste than laminate because you can't use offcuts as easily. Always keep leftover packs for future repairs.
How many square metres in a pack of laminate?
Standard laminate packs cover 1.8 - 2.4 m² each. Most are around 2.2 m². Always check the pack label - the calculator lets you enter the exact coverage. Premium thicker laminates (12 mm) tend to cover less per pack.
How much underlay do I need?
Buy underlay that covers the same area as your floor plus 5% overlap. For a 20 m² room, that is 21 m². If the underlay is sold in rolls, check the roll area - typically 15 m² per roll, so you need 2 rolls. Underlay is cheap insurance - never skip it.
How do I measure an L-shaped room for flooring?
Split the L into two rectangles. Measure each one, calculate the area of each, then add them together. For example, an L with a 6 × 4 leg and a 3 × 2 leg has area 24 + 6 = 30 m². Add 10% wastage for the extra cuts at the inner corner.
Should I lay planks along the length or width of the room?
For most rooms, lay planks along the length (in the direction of the longest wall). This makes the room feel longer and reduces the number of cuts. If the room has a strong light source like a big window, lay planks parallel to the light to hide joints. Never lay planks across a narrow passage - it looks choppy.
Do I need an expansion gap for laminate or engineered wood?
Yes - 10 mm minimum around the entire perimeter for floating floors. This gap lets the floor expand and contract with humidity without buckling. The gap is hidden by skirting or scotia beading. If you skip it, your floor will fail within a year in most climates.
How much skirting do I need?
Calculate the perimeter of the room, then deduct the width of each door (0.9 m for interior doors). Add 10% for cuts. For a 5 × 4 m room with 1 door: perimeter 18 m - 0.9 m = 17.1 m + 10% = 18.8 m. Skirting boards come in 2.4 m or 3 m lengths. Round up to the nearest full board.
What is the difference between scotia beading and skirting board?
Skirting board is the wooden trim that runs along the bottom of a wall. It is usually fitted before flooring. Scotia beading is a smaller decorative moulding that goes on top of the floor at the edge of the wall to hide the expansion gap. Beading is used when you don't want to remove and refit skirting.
Can I install laminate over underfloor heating?
Yes, but only if the laminate is rated for it and the underlay is designed for UFH. Never use thick foam or fiberboard underlay with UFH - it blocks the heat. Use a thin (2 mm) foil underlay or a specific UFH underlay. The floor surface temperature must not exceed 27°C.
How long does flooring take to install?
Laminate: 10 - 15 m² per hour for a confident DIYer, up to 25 m² per hour for a pro. Engineered wood: 6 - 10 m² per hour. Solid hardwood (nailed): 4 - 6 m² per hour. Carpet: professional install only. Add 20% for rooms with many corners or doorways.
Should I buy extra flooring for future repairs?
Yes - keep at least 1 full pack in storage after the install. Flooring dye lots vary between production runs, so if you need to replace a damaged plank in 3 years, the same model may look slightly different. Store the spare pack flat in a dry room, away from moisture.
How many planks are in a pack?
It depends on plank size and pack area. A typical laminate pack covers 2.2 m² and contains 8 - 10 planks. Engineered wood packs often contain 6 - 8 planks for 2 - 2.5 m². LVT packs usually contain 10 - 20 tiles or planks. Always check the pack's total coverage rather than plank count.
Do I need to acclimatise flooring before installing?
Yes for any wood-based floor. Leave the packs flat in the room for 48 - 72 hours before installation, at normal room temperature. This lets the planks adjust to the room's humidity, so they don't expand or contract after installation. Skip this and your floor is more likely to develop gaps or buckle.
References & Standards
- BS 8201 - Code of practice for flooring of timber, timber products and wood-based panel products
- BS 5325 - Code of practice for installation of textile floor coverings
- BS EN 13329 - Laminate floor coverings
- BS EN 13489 - Wood flooring and parquet
- BS EN ISO 10582 - Resilient floor coverings - heterogeneous poly(vinyl chloride) floor coverings
- ASTM F1700 - Standard Specification for Solid Vinyl Floor Tile
- AS 1884 - Floor coverings - Resilient sheet and tiles - Installation practices
- NIS 550 - Nigerian Industrial Standard Building Code