Calculate m2 & sq ft: Walls–Floors–Ceilings 2025

How to Calculate m² & sq ft (Flooring, Panels, Profiles)

Accurate m²/sq ft take-offs save budget, prevent delays, and ensure smooth installs. This guide covers wall panels (sheet/board), slat wall profiles (strips), flooring, and ceiling tiles/panels with clear formulas, m² ⇄ sq ft conversions (sq ft = m² × 10.7639; m² = sq ft × 0.092903), waste percentages, and real-world examples (including L-shapes and trapezoids).

Quick Definitions

1. Floor m² = width × length
2. Single wall m² = wall width × height − openings
3. Room wall m² = 2×(width+length) × height − openings
4. Recommended waste: Flat panels 5–7% • Slat profiles 7–10% • Patterned floors 8–12% • Many corners/alcoves 10–15%
5. Round up to full box: After adding waste, round up to the next full box m².
6. Accessories take-off: Skirting/perimeter ≈ room perimeter; corner/finishing profiles by edge length.

1) Wall Panel (Sheet/Board) – m²

Steps

1. Gross m²: wall width × height
2. Subtract openings: door + window m²
3. Add waste: usually 5–7%
4. Pieces: Net m² ÷ piece m² (e.g., 60×60 cm = 0.36 m²)
5. Round up to full box by product box m².

Example

1. Wall: 3.00 × 2.70 = 8.10 m² (no openings)
2. Waste 7% → 8.10 × 1.07 = 8.67 m²
3. Piece 0.36 m² → 8.67 ÷ 0.36 = 24.08 ≈ 25 pcs
4. If box = 1.80 m² → 8.67 ÷ 1.80 = 4.82 ≈ 5 boxes

Accessory note

1. Inside/outside corner profile: wall height each (× number of corners)
2. Finishing/trim: total length of exposed edges

2) Slat Wall Profile (Strip) – Quantity

Rule: Module = slat width + spacing

1. Qty (vertical) = wall width ÷ module → round up
2. Length per slat = wall height
3. Waste: 7–10%

Example (vertical)

1. Wall: 300 cm wide, 270 cm high
2. Slat 27 mm, spacing 13 mm → 40 mm module (4 cm)
3. Qty = 300 ÷ 4 = 75 slats
4. Waste 7% → 80 slats (270 cm length)

Tip

Smaller spacing = more slats. Fix the module for the entire surface. Add extra metres if you frame top/bottom or cross columns.

3) Flooring (Laminate/Vinyl) – m² & Boxes

Steps

1. Area: width × length
2. Waste: 5–7% straight; 10–12% herringbone/chevron
3. Boxes: (net + waste m²) ÷ box m², round up
4. Skirting: room perimeter = 2×(width+length) − door widths
5. Underlay: net floor m² + ~5%

Example

1. Room: 3.6 × 4.2 = 15.12 m²
2. Waste 8% → 16.33 m²
3. Box 2.20 m² → 16.33 ÷ 2.20 = 7.42 ≈ 8 boxes
4. Skirting: 2×(3.6+4.2) = 15.6 m

4) Ceiling Panels/Tiles – m² & Pieces

Piece m² reference

1. 60×60 cm = 0.36 m²/piece
2. 60×120 cm = 0.72 m²/piece

Steps

1. Area: width × length
2. Pieces: area ÷ piece m² → round up
3. Waste: 5–7% for edge cuts
4. Perimeter profile (L/U): room perimeter = 2×(width+length)

Example

1. Ceiling: 4.0 × 5.0 = 20.0 m²
2. 60×60 tiles: 20 ÷ 0.36 = 55.6 ≈ 56 pcs
3. Waste 7% → 60 pcs
4. Perimeter: 18 m

5) Irregular Shapes

L-shaped room

1. Split into rectangles, calculate each, sum, then add waste and round up.

A: 3.0 × 4.0 = 12.0 m²; B: 2.0 × 1.5 = 3.0 m² → 15.0 m²

Trapezoid wall

1. Formula: (top + bottom) / 2 × height

(2.6 + 3.0)/2 × 2.7 = 7.29 m²

Triangle surface

1. Formula: (base × height) / 2

(3.0 × 2.0)/2 = 3.0 m²

6) Waste (Off-cut) Quick Table

Most products are sold by box m² — always round your net+waste m² up to full boxes.

7) Common Mistakes & Fixes

1. Not subtracting openings: inflates m² → always deduct door/window areas.
2. No waste added: risk of shade/lot mismatch & delays → add 5–12% (complex surfaces up to 15%).
3. Not rounding to full boxes: leads to shortage → always round up.
4. Changing slat spacing on site: breaks quantity plan → lock the module early.
5. Ignoring perimeter accessories: unfinished look → plan skirting, corners, trims from day one.

Square Metre (Sq ft) Usage: Calculations and Conversions

Quick rules

1. Floor area (sq ft) = width (ft) × length (ft)
2. Wall area (sq ft) = wall width (ft) × height (ft) − openings (ft²)
3. Convert m² → sq ft: sq ft = m² × 10.7639
4. Convert sq ft → m²: m² = sq ft × 0.092903
5. Waste (off-cut) rates are the same as in m² (flat panels 5–7%, slats 7–10%, patterned floors 8–12%, complex cuts 10–15%).
6. If boxes are sold in m²/box, convert your sq ft result back to m² to choose the box count (then round up).

Examples

Flooring (room measured in meters, in sq ft)

1. Room: 3.6 m × 4.2 m = 15.12 m²
2. Waste 8% → 16.33 m²
3. Convert to sq ft: 16.33 × 10.7639 ≈ 176.0 sq ft
4. If box = 23.7 sq ft/box → 176.0 ÷ 23.7 = 7.4 ≈ 8 boxes

Slat wall (dimensions in feet)

1. Wall: 10 ft wide, 8.9 ft high → 89 sq ft (openings excluded)
2. Waste 7% → 95.2 sq ft
3. If product quoted in m², convert: 95.2 × 0.092903 ≈ 8.84 m² → round up to full boxes.

Ceiling tiles

1. Ceiling: 12 ft × 16 ft = 192 sq ft
2. 60×60 cm tiles = 0.36 m² = 3.875 sq ft/piece
3. Pieces = 192 ÷ 3.875 ≈ 49.5 → 50 pcs, then add 5–7% for edge cuts → 53–54 pcs.

m² → sq ft (approx.)

1. 5 m² ≈ 53.82 sq ft
2. 10 m² ≈ 107.64 sq ft
3. 15 m² ≈ 161.46 sq ft
4. 20 m² ≈ 215.28 sq ft
5. 50 m² ≈ 538.20 sq ft

sq ft → m² (approx.)

1. 100 sq ft ≈ 9.29 m²
2. 150 sq ft ≈ 13.94 m²
3. 200 sq ft ≈ 18.58 m²
4. 500 sq ft ≈ 46.45 m²
5. 1,000 sq ft ≈ 92.90 m²

Best practice: show both units together on product and estimate pages, e.g. “75 m² / 807 sq ft”.

FAQ

Do I always subtract openings?

Yes. Net m² = gross area minus door/window areas. Very small niches can be ignored depending on application.

How do I choose waste percentage?

By number of cuts, corners/alcoves and pattern direction. Flat panels 5–7%, slat profiles 7–10%, patterned floors 8–12%, complex surfaces 10–15%.

What happens if I change the slat spacing later?

m² stays similar but quantity changes. For visual rhythm and correct take-off, keep one module across the wall.

How do I calculate skirting and ceiling perimeter profiles?

Usually the room perimeter (2×(width+length)). Subtract door widths for skirting.

Do I need to convert to sq ft for the UK?

Common practice is to show both: e.g., 75 m² / 807 sq ft. Listings often lead with sq ft, while specifications and drawings typically use m².

How do I convert m² to sq ft (and back)?

Use: sq ft = m² × 10.7639 and m² = sq ft × 0.092903. Round to 1–2 decimals for marketing materials; 3–4 decimals for technical documents.

My room is measured in feet—how do I get sq ft?

Multiply width (ft) × length (ft). For walls, use wall width (ft) × height (ft) − openings (ft²) to get the net area.

Boxes are sold in m² but my area is in sq ft—what now?

Convert sq ft → m² using × 0.092903, add waste, then divide by the box m² value and round up to whole boxes.

What waste (off-cut) % should I add in sq ft?

Use the same rates as for m²: flat panels 5–7%, slat profiles 7–10%, patterned floors 8–12%, and complex cuts 10–15%.

How many boxes/pieces do I need?

Boxes: (net+waste m²) ÷ box m², round up.

Tiles/panels: area ÷ piece m², round up and add waste.

With Acarkon: You Imagine, We Calculate

Skip the math—Acarkon prepares the measurements, boxes, waste and accessory list for you. Tell us the surface and look you want; we’ll deliver accurate m², correct box/quantity and a complete accessory plan end-to-end.

Online orders & samples: Acarkon Store — https://acarkonstore.com/