How to Calculate Quantities from Room Measurements
Formulas for turning room dimensions into quantities for painting, ceilings, flooring, wardrobes, kitchens and skirting.
Floor and ceiling
Floor area and ceiling area = length × width. For a 12 × 10 ft room, that's 120 sq.ft.
Walls
Wall area = 2 × (length + width) × height, minus doors and windows. Use this for painting and wallpaper.
Skirting and cornices
Running length = 2 × (length + width), minus door widths.
Wardrobes and units
Wardrobes are usually quantified by front area (width × height). Kitchens and TV units by running feet along the wall.