How to estimate paint for walls and ceilings
Underestimating paint leaves you rushing to the hardware store midway through cutting in, while overestimating wastes money on expensive tinted cans that dry out in the garage. A standard litre of interior acrylic wall paint typically covers 12 to 16 square metres on smooth sealed surfaces.
Calculate total wall surface area by multiplying the perimeter of the room by the ceiling height, then deduct the area of large windows and door openings. Remember that almost all interior walls require two full coats for uniform colour depth and durability.
Bare plasterboard, repaired patches, and dramatic colour transitions always require a dedicated primer-sealer undercoat first. Skipping the undercoat on new drywall will cause the topcoat to soak unevenly into joint compound, creating patchy flash marks.