How to Measure Your Home Before a Decoration Project

Correct Square-Metre Calculation

Measuring correctly before ordering paint or wallpaper eliminates both waste and the problem of insufficient material.

The Basic Formula

Area = Perimeter × Ceiling Height
The perimeter of a room: (Width + Length) × 2
For a room with a 12 m perimeter and a standard 2.70 m ceiling: 12 × 2.70 = 32.4 m²

Deducting Doors and Windows

Each standard door takes up about 1.8 m², and a standard window between 1.2 and 2.4 m². These values are deducted from the total area. Calculating this matters in rooms with many windows.

Wallpaper Calculation

Standard wallpaper roll width is 53 cm. If there is a pattern repeat, the waste that occurs in each roll must be taken into account. Practical rule: add a 10–15% waste allowance to your square-metre calculation.

Paint Calculation

Most quality paints offer a coverage of 8–12 m² per litre (for 2 coats). Divide the square metres you calculated by this value to determine the amount you need.